Techniques for updating reference signals

ABSTRACT

Methods, systems, and devices for wireless communications are described. The described techniques provide for dynamic updates to beam failure detection (BFD) reference signals (RSs) and path loss RS using medium access control-control element (MAC-CE) or downlink control information (DCI). For example, the quasi co-location (QCL) of periodic CSI-RS may be dynamically updated by the MAC-CE or DCI when the periodic CSI-RS is for BFD RS. Also, a semi-persistent CSI-RS or aperiodic CSI-RS may act as a BFD RS. An enhanced update procedure may be used to update the path loss RS dynamically using MAC-CE or DCI. In some cases, the path loss RS parameters updated via MAC-CE or DCI may overwrite the previously RRC configured path loss RS parameters. In another example, if the path loss RS is not configured, then the path loss RS by default may be the spatial relation reference signal of the corresponding uplink beam.

CROSS REFERENCE

The present application for patent claims the benefit of U.S.Provisional Patent Application No. 62/843,330 by ZHOU et al., entitled“TECHNIQUES FOR UPDATING REFERENCE SIGNALS,” filed May 3, 2019, assignedto the assignee hereof, and expressly incorporated by reference herein.

FIELD OF INVENTION

The following relates generally to wireless communications, and morespecifically to techniques for updating reference signals.

BACKGROUND

Wireless communications systems are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be capable ofsupporting communication with multiple users by sharing the availablesystem resources (e.g., time, frequency, and power). Examples of suchmultiple-access systems include fourth generation (4G) systems such asLong Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, orLTE-A Pro systems, and fifth generation (5G) systems which may bereferred to as New Radio (NR) systems. These systems may employtechnologies such as code division multiple access (CDMA), time divisionmultiple access (TDMA), frequency division multiple access (FDMA),orthogonal frequency division multiple access (OFDMA), or discreteFourier transform spread orthogonal frequency division multiplexing(DFT-S-OFDM). A wireless multiple-access communications system mayinclude a number of base stations or network access nodes, eachsimultaneously supporting communication for multiple communicationdevices, which may be otherwise known as user equipment (UE).

In some cases, wireless communications systems may use reference signalsfor various purposes, such as beam failure detection, path lossestimation, channel state signaling, or the like. In some cases,reference signal configurations may be semi-statically signaled from abase station to a UE (e.g., using radio resource control (RRC)signaling). Such signaling may also indicate particular sets ofresources for a type of reference signal. However, as various systemparameters associated with the reference signals may change morefrequently than the signaling is received, reconfiguring referencesignals using semi-static signaling techniques may result in systemlatency and inefficient communications.

SUMMARY

The described techniques relate to improved methods, systems, devices,and apparatuses that support techniques for updating reference signals.Generally, the described techniques provide for dynamic updates toreference signals, including beam failure detection reference signals(BFD-RSs) and path loss reference signals, through a medium accesscontrol (MAC) control element (MAC-CE) or downlink control information(DCI). In such cases, a particular MAC-CE or DCI format for updatingreference signal configurations may be used to quickly update aconfiguration of a reference signal, which may avoid reconfigurationlatency (such as when reference signals are reconfigured via radioresource control (RRC) signaling) and/or reduce signaling overhead inthe system. As an example, when a quasi co-location (QCL) parameter of amonitored control resource set (CORESET) changes, the QCL of acorresponding BFD-RS may be dynamically updated via the MAC-CE or DCIbased on the change. For instance, a periodic channel state informationreference signal (CSI-RS) may be dynamically updated by the MAC-CE orDCI, where the periodic CSI-RS may be utilized for the BFD-RS. Inanother example, a semi-persistent CSI-RS or aperiodic CSI-RS may beconfigured as the BFD-RS, and their QCL may also be quickly updated byMAC-CE or DCI when the QCL of the CORESET changes.

Enhanced procedures for updating path loss reference signals are alsodescribed. In such cases, a path loss reference signal may bedynamically updated using MAC-CE or DCI. In some examples, path lossreference signal parameters updated via MAC-CE or DCI may overwritepreviously RRC-configured path loss reference signal parameters. Inanother example, if the path loss reference signal is not configured(such as when the configuration of the path loss reference signal isoptional), then the path loss reference signal may default to a spatialrelation reference signal of a corresponding uplink beam. Specifically,if the path loss reference signal is not configured, then the path lossreference signal may be the spatial reference signal for a spatialrelation (e.g., corresponding to a beam) of an uplink channel resourcethat is configured via RRC.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a system for wireless communicationsthat supports techniques for updating reference signals in accordancewith aspects of the present disclosure.

FIG. 2 illustrates an example of a system for wireless communicationsthat supports techniques for updating reference signals in accordancewith aspects of the present disclosure.

FIG. 3 illustrates an example of a process flow that supports techniquesfor updating reference signals in accordance with aspects of the presentdisclosure.

FIG. 4 illustrates an example of a process flow that supports techniquesfor updating reference signals in accordance with aspects of the presentdisclosure.

FIG. 5 illustrates an example of a process flow that supports techniquesfor updating reference signals in accordance with aspects of the presentdisclosure.

FIG. 6 illustrates an example of an architecture that supportstechniques for updating reference signals in accordance with aspects ofthe present disclosure.

FIGS. 7 and 8 show block diagrams of devices that support techniques forupdating reference signals in accordance with aspects of the presentdisclosure.

FIG. 9 shows a block diagram of a communications manager that supportstechniques for updating reference signals in accordance with aspects ofthe present disclosure.

FIG. 10 shows a diagram of a system including a device that supportstechniques for updating reference signals in accordance with aspects ofthe present disclosure.

FIGS. 11 and 12 show block diagrams of devices that support techniquesfor updating reference signals in accordance with aspects of the presentdisclosure.

FIG. 13 shows a block diagram of a communications manager that supportstechniques for updating reference signals in accordance with aspects ofthe present disclosure.

FIG. 14 shows a diagram of a system including a device that supportstechniques for updating reference signals in accordance with aspects ofthe present disclosure.

FIGS. 15 through 20 show flowcharts illustrating methods that supporttechniques for updating reference signals in accordance with aspects ofthe present disclosure.

DETAILED DESCRIPTION

In some communication systems, RRC reconfiguration may be used when atransmission configuration indicator (TCI) state for a periodic CSI-RSchanges. The RRC reconfiguration may update the TCI state ID and a quasico-location (QCL) parameter for a channel state information referencesignal (CSI-RS) (e.g., QCL type and/or QCL source). In some cases, beamfailure detection reference signals (BFD-RSs) may be periodicallytransmitted and may be explicitly configured by RRC signaling orimplicitly configured in a TCI state of a monitored control resource set(CORESET). In some examples, the BFD-RSs may include a periodic CSI-RSand a synchronization signal block (SSB).

In beam failure recovery, when the QCL of a monitored CORESET changes,the corresponding periodic BFD-RS may also need to be changed (e.g., tohave a similar QCL). However, in some cases, the BFD-RS may only beupdated either through semi-static RRC reconfiguration signaling orthrough the configuration of a large number of periodic CSI-RSs (e.g.,with a large number of TCI states). But, RRC reconfiguration mayintroduce reconfiguration latency, and the configuration of a largenumber of periodic CSI-RSs may increase the signaling overhead of thesystem. For instance, if a BFD-RS corresponding to a monitored CORESETis explicitly configured by RRC signaling, either an updated BFD-RS maybe configured with QCL matching that of the monitored CORESET, or a QCLof the original BFD-RS may be reconfigured, where both the updatedBFD-RS and the reconfigured QCL may be conveyed using RRC signaling.Alternatively, if the corresponding BFD-RS is implicitly configured in aTCI state of the monitored CORESET, the BFD-RS is the periodic CSI-RS inthe new TCI state of the monitored CORESET. In this case, the system mayneed to configure periodic CSI-RSs for all TCI states of the CORESET.

In some systems, a path loss reference signal for power control may alsobe RRC configured. For example, a path loss reference signal may be RRCconfigured per a physical uplink control channel (PUCCH) spatialrelation for PUCCH power control. However, this may be an inefficientupdate methodology and may lead to latency issues when the path lossreference signal changes (or the resources used for the path lossreference signal changes). Likewise, for physical uplink shared channel(PUSCH) power control, path loss reference signal may be RRC configuredusing a sounding reference signal (SRS) resource indicator (SRI). ForSRS power control, path loss reference signal may be RRC configured perSRS resource set for SRS power control. Thus, when a change of the pathloss reference signal occurs in uplink power control, an RRCreconfiguration may be needed, but this reconfiguration may introducelatency into the system.

As described herein, a particular MAC-CE or DCI format that isassociated with updating reference signal configuration may be used toupdate the BFD-RS to avoid reconfiguration latency and reduce signalingoverhead in the system. For example, the QCL of periodic CSI-RS may bedynamically updated by the MAC-CE or DCI, at least when the periodicCSI-RS is for BFD-RS. Thus, the QCL of the original BFD-RS may bequickly updated without a large number of periodic CSI-RS. In anotherexample, a semi-persistent CSI-RS or aperiodic CSI-RS may act as aBFD-RS, and if the semi-persistent CSI-RS or aperiodic CSI-RS areexplicitly configured as BFD-RS, their QCL may be quickly updated byMAC-CE or DCI.

In further aspects, an enhanced update procedure for path loss referencesignals may be used to overcome the described delays associated with RRCreconfiguration. For example, a path loss reference signal may beupdated dynamically by MAC-CE or DCI such that the path loss referencesignal may overwrite the previously RRC configured path loss referencesignal. In another example, if the path loss reference signal is notconfigured, then the path loss reference signal may, by default, be aspatial relation reference signal of the corresponding uplink beam.Specifically, if the path loss reference signal is not configured in thePUCCH spatial relation for PUCCH power control, then the path lossreference signal may be the spatial reference signal in the spatialrelation of the corresponding PUCCH resource. If the path loss referencesignal is not configured per SRI for PUSCH power control, then the pathloss reference signal may be the spatial reference signal in the spatialrelation of the SRS resource indicated by SRI.

Aspects of the disclosure are initially described in the context of awireless communications system. Aspects of the disclosure are furtherillustrated by and described with reference to apparatus diagrams,system diagrams, and flowcharts that relate to techniques for updatingreference signals.

FIG. 1 illustrates an example of a wireless communications system 100that supports techniques for updating reference signals in accordancewith aspects of the present disclosure. The wireless communicationssystem 100 includes base stations 105, UEs 115, and a core network 130.In some examples, the wireless communications system 100 may be a LongTerm Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-APro network, or a New Radio (NR) network. In some cases, wirelesscommunications system 100 may support enhanced broadband communications,ultra-reliable (e.g., mission critical) communications, low latencycommunications, or communications with low-cost and low-complexitydevices.

Base stations 105 may wirelessly communicate with UEs 115 via one ormore base station antennas. Base stations 105 described herein mayinclude or may be referred to by those skilled in the art as a basetransceiver station, a radio base station, an access point, a radiotransceiver, a NodeB, an eNodeB (eNB), a next-generation NodeB orgiga-NodeB (either of which may be referred to as a gNB), a Home NodeB,a Home eNodeB, or some other suitable terminology. Wirelesscommunications system 100 may include base stations 105 of differenttypes (e.g., macro or small cell base stations). The UEs 115 describedherein may be able to communicate with various types of base stations105 and network equipment including macro eNBs, small cell eNBs, gNBs,relay base stations, and the like.

Each base station 105 may be associated with a particular geographiccoverage area 110 in which communications with various UEs 115 issupported. Each base station 105 may provide communication coverage fora respective geographic coverage area 110 via communication links 125,and communication links 125 between a base station 105 and a UE 115 mayutilize one or more carriers. Communication links 125 shown in wirelesscommunications system 100 may include uplink transmissions from a UE 115to a base station 105, or downlink transmissions from a base station 105to a UE 115. Downlink transmissions may also be called forward linktransmissions while uplink transmissions may also be called reverse linktransmissions.

The geographic coverage area 110 for a base station 105 may be dividedinto sectors making up a portion of the geographic coverage area 110,and each sector may be associated with a cell. For example, each basestation 105 may provide communication coverage for a macro cell, a smallcell, a hot spot, or other types of cells, or various combinationsthereof. In some examples, a base station 105 may be movable andtherefore provide communication coverage for a moving geographiccoverage area 110. In some examples, different geographic coverage areas110 associated with different technologies may overlap and overlappinggeographic coverage areas 110 associated with different technologies maybe supported by the same base station 105 or by different base stations105. The wireless communications system 100 may include, for example, aheterogeneous LTE/LTE-A/LTE-A Pro or NR network in which different typesof base stations 105 provide coverage for various geographic coverageareas 110.

The term “cell” refers to a logical communication entity used forcommunication with a base station 105 (e.g., over a carrier), and may beassociated with an identifier for distinguishing neighboring cells(e.g., a physical cell identifier (PCID), a virtual cell identifier(VCID)) operating via the same or a different carrier. In some examples,a carrier may support multiple cells, and different cells may beconfigured according to different protocol types (e.g., machine-typecommunication (MTC), narrowband Internet-of-Things (NB-IoT), enhancedmobile broadband (eMBB), or others) that may provide access fordifferent types of devices. In some cases, the term “cell” may refer toa portion of a geographic coverage area 110 (e.g., a sector) over whichthe logical entity operates.

UEs 115 may be dispersed throughout the wireless communications system100, and each UE 115 may be stationary or mobile. A UE 115 may also bereferred to as a mobile device, a wireless device, a remote device, ahandheld device, or a subscriber device, or some other suitableterminology, where the “device” may also be referred to as a unit, astation, a terminal, or a client. A UE 115 may also be a personalelectronic device such as a cellular phone, a personal digital assistant(PDA), a tablet computer, a laptop computer, or a personal computer. Insome examples, a UE 115 may also refer to a wireless local loop (WLL)station, an Internet of Things (IoT) device, an Internet of Everything(IoE) device, or an MTC device, or the like, which may be implemented invarious articles such as appliances, vehicles, meters, or the like.

Some UEs 115, such as MTC or IoT devices, may be low cost or lowcomplexity devices, and may provide for automated communication betweenmachines (e.g., via Machine-to-Machine (M2M) communication). M2Mcommunication or MTC may refer to data communication technologies thatallow devices to communicate with one another or a base station 105without human intervention. In some examples, M2M communication or MTCmay include communications from devices that integrate sensors or metersto measure or capture information and relay that information to acentral server or application program that can make use of theinformation or present the information to humans interacting with theprogram or application. Some UEs 115 may be designed to collectinformation or enable automated behavior of machines. Examples ofapplications for MTC devices include smart metering, inventorymonitoring, water level monitoring, equipment monitoring, healthcaremonitoring, wildlife monitoring, weather and geological eventmonitoring, fleet management and tracking, remote security sensing,physical access control, and transaction-based business charging.

Some UEs 115 may be configured to employ operating modes that reducepower consumption, such as half-duplex communications (e.g., a mode thatsupports one-way communication via transmission or reception, but nottransmission and reception simultaneously). In some examples half-duplexcommunications may be performed at a reduced peak rate. Other powerconservation techniques for UEs 115 include entering a power saving“deep sleep” mode when not engaging in active communications, oroperating over a limited bandwidth (e.g., according to narrowbandcommunications). In some cases, UEs 115 may be designed to supportcritical functions (e.g., mission critical functions), and a wirelesscommunications system 100 may be configured to provide ultra-reliablecommunications for these functions.

In some cases, a UE 115 may also be able to communicate directly withother UEs 115 (e.g., using a peer-to-peer (P2P) or device-to-device(D2D) protocol). One or more of a group of UEs 115 utilizing D2Dcommunications may be within the geographic coverage area 110 of a basestation 105. Other UEs 115 in such a group may be outside the geographiccoverage area 110 of a base station 105 or be otherwise unable toreceive transmissions from a base station 105. In some cases, groups ofUEs 115 communicating via D2D communications may utilize a one-to-many(1:M) system in which each UE 115 transmits to every other UE 115 in thegroup. In some cases, a base station 105 facilitates the scheduling ofresources for D2D communications. In other cases, D2D communications arecarried out between UEs 115 without the involvement of a base station105.

Base stations 105 may communicate with the core network 130 and with oneanother. For example, base stations 105 may interface with the corenetwork 130 through backhaul links 132 (e.g., via an S1, N2, N3, orother interface). Base stations 105 may communicate with one anotherover backhaul links 134 (e.g., via an X2, Xn, or other interface) eitherdirectly (e.g., directly between base stations 105) or indirectly (e.g.,via core network 130).

The core network 130 may provide user authentication, accessauthorization, tracking, Internet Protocol (IP) connectivity, and otheraccess, routing, or mobility functions. The core network 130 may be anevolved packet core (EPC), which may include at least one mobilitymanagement entity (MME), at least one serving gateway (S-GW), and atleast one Packet Data Network (PDN) gateway (P-GW). The MME may managenon-access stratum (e.g., control plane) functions such as mobility,authentication, and bearer management for UEs 115 served by basestations 105 associated with the EPC. User IP packets may be transferredthrough the S-GW, which itself may be connected to the P-GW. The P-GWmay provide IP address allocation as well as other functions. The P-GWmay be connected to the network operators IP services. The operators IPservices may include access to the Internet, Intranet(s), an IPMultimedia Subsystem (IMS), or a Packet-Switched (PS) Streaming Service.

At least some of the network devices, such as a base station 105, mayinclude subcomponents such as an access network entity, which may be anexample of an access node controller (ANC). Each access network entitymay communicate with UEs 115 through a number of other access networktransmission entities, which may be referred to as a radio head, a smartradio head, or a transmission/reception point (TRP). In someconfigurations, various functions of each access network entity or basestation 105 may be distributed across various network devices (e.g.,radio heads and access network controllers) or consolidated into asingle network device (e.g., a base station 105).

Wireless communications system 100 may operate using one or morefrequency bands, typically in the range of 300 megahertz (MHz) to 300gigahertz (GHz). Generally, the region from 300 MHz to 3 GHz is known asthe ultra-high frequency (UHF) region or decimeter band, since thewavelengths range from approximately one decimeter to one meter inlength. UHF waves may be blocked or redirected by buildings andenvironmental features. However, the waves may penetrate structuressufficiently for a macro cell to provide service to UEs 115 locatedindoors. Transmission of UHF waves may be associated with smallerantennas and shorter range (e.g., less than 100 km) compared totransmission using the smaller frequencies and longer waves of the highfrequency (HF) or very high frequency (VHF) portion of the spectrumbelow 300 MHz.

Wireless communications system 100 may also operate in a super highfrequency (SHF) region using frequency bands from 3 GHz to 30 GHz, alsoknown as the centimeter band. The SHF region includes bands such as the5 GHz industrial, scientific, and medical (ISM) bands, which may be usedopportunistically by devices that may be capable of toleratinginterference from other users.

Wireless communications system 100 may also operate in an extremely highfrequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz),also known as the millimeter band. In some examples, wirelesscommunications system 100 may support millimeter wave (mmW)communications between UEs 115 and base stations 105, and EHF antennasof the respective devices may be even smaller and more closely spacedthan UHF antennas. In some cases, this may facilitate use of antennaarrays within a UE 115. However, the propagation of EHF transmissionsmay be subject to even greater atmospheric attenuation and shorter rangethan SHF or UHF transmissions. Techniques disclosed herein may beemployed across transmissions that use one or more different frequencyregions, and designated use of bands across these frequency regions maydiffer by country or regulating body.

In some cases, wireless communications system 100 may utilize bothlicensed and unlicensed radio frequency spectrum bands. For example,wireless communications system 100 may employ License Assisted Access(LAA), LTE-Unlicensed (LTE-U) radio access technology, or NR technologyin an unlicensed band such as the 5 GHz ISM band. When operating inunlicensed radio frequency spectrum bands, wireless devices such as basestations 105 and UEs 115 may employ listen-before-talk (LBT) proceduresto ensure a frequency channel is clear before transmitting data. In somecases, operations in unlicensed bands may be based on a carrieraggregation configuration in conjunction with component carriersoperating in a licensed band (e.g., LAA). Operations in unlicensedspectrum may include downlink transmissions, uplink transmissions,peer-to-peer transmissions, or a combination of these. Duplexing inunlicensed spectrum may be based on frequency division duplexing (FDD),time division duplexing (TDD), or a combination of both.

In some examples, base station 105 or UE 115 may be equipped withmultiple antennas, which may be used to employ techniques such astransmit diversity, receive diversity, multiple-input multiple-output(MIMO) communications, or beamforming. For example, wirelesscommunications system 100 may use a transmission scheme between atransmitting device (e.g., a base station 105) and a receiving device(e.g., a UE 115), where the transmitting device is equipped withmultiple antennas and the receiving device is equipped with one or moreantennas. MIMO communications may employ multipath signal propagation toincrease the spectral efficiency by transmitting or receiving multiplesignals via different spatial layers, which may be referred to asspatial multiplexing. The multiple signals may, for example, betransmitted by the transmitting device via different antennas ordifferent combinations of antennas. Likewise, the multiple signals maybe received by the receiving device via different antennas or differentcombinations of antennas. Each of the multiple signals may be referredto as a separate spatial stream and may carry bits associated with thesame data stream (e.g., the same codeword) or different data streams.Different spatial layers may be associated with different antenna portsused for channel measurement and reporting. MIMO techniques includesingle-user MIMO (SU-MIMO) where multiple spatial layers are transmittedto the same receiving device, and multiple-user MIMO (MU-MIMO) wheremultiple spatial layers are transmitted to multiple devices.

Beamforming, which may also be referred to as spatial filtering,directional transmission, or directional reception, is a signalprocessing technique that may be used at a transmitting device or areceiving device (e.g., a base station 105 or a UE 115) to shape orsteer an antenna beam (e.g., a transmit beam or receive beam) along aspatial path between the transmitting device and the receiving device.Beamforming may be achieved by combining the signals communicated viaantenna elements of an antenna array such that signals propagating atparticular orientations with respect to an antenna array experienceconstructive interference while others experience destructiveinterference. The adjustment of signals communicated via the antennaelements may include a transmitting device or a receiving deviceapplying certain amplitude and phase offsets to signals carried via eachof the antenna elements associated with the device. The adjustmentsassociated with each of the antenna elements may be defined by abeamforming weight set associated with a particular orientation (e.g.,with respect to the antenna array of the transmitting device orreceiving device, or with respect to some other orientation).

In one example, a base station 105 may use multiple antennas or antennaarrays to conduct beamforming operations for directional communicationswith a UE 115. For instance, some signals (e.g., synchronizationsignals, reference signals, beam selection signals, or other controlsignals) may be transmitted by a base station 105 multiple times indifferent directions, which may include a signal being transmittedaccording to different beamforming weight sets associated with differentdirections of transmission. Transmissions in different beam directionsmay be used to identify (e.g., by the base station 105 or a receivingdevice, such as a UE 115) a beam direction for subsequent transmissionand/or reception by the base station 105.

Some signals, such as data signals associated with a particularreceiving device, may be transmitted by a base station 105 in a singlebeam direction (e.g., a direction associated with the receiving device,such as a UE 115). In some examples, the beam direction associated withtransmissions along a single beam direction may be determined based atleast in in part on a signal that was transmitted in different beamdirections. For example, a UE 115 may receive one or more of the signalstransmitted by the base station 105 in different directions, and the UE115 may report to the base station 105 an indication of the signal itreceived with a highest signal quality, or an otherwise acceptablesignal quality. Although these techniques are described with referenceto signals transmitted in one or more directions by a base station 105,a UE 115 may employ similar techniques for transmitting signals multipletimes in different directions (e.g., for identifying a beam directionfor subsequent transmission or reception by the UE 115), or transmittinga signal in a single direction (e.g., for transmitting data to areceiving device).

A receiving device (e.g., a UE 115, which may be an example of a mmWreceiving device) may try multiple receive beams when receiving varioussignals from the base station 105, such as synchronization signals,reference signals, beam selection signals, or other control signals. Forexample, a receiving device may try multiple receive directions byreceiving via different antenna subarrays, by processing receivedsignals according to different antenna subarrays, by receiving accordingto different receive beamforming weight sets applied to signals receivedat a plurality of antenna elements of an antenna array, or by processingreceived signals according to different receive beamforming weight setsapplied to signals received at a plurality of antenna elements of anantenna array, any of which may be referred to as “listening” accordingto different receive beams or receive directions. In some examples areceiving device may use a single receive beam to receive along a singlebeam direction (e.g., when receiving a data signal). The single receivebeam may be aligned in a beam direction determined based at least inpart on listening according to different receive beam directions (e.g.,a beam direction determined to have a highest signal strength, highestsignal-to-noise ratio, or otherwise acceptable signal quality based atleast in part on listening according to multiple beam directions).

In some cases, the antennas of a base station 105 or UE 115 may belocated within one or more antenna arrays, which may support MIMOoperations, or transmit or receive beamforming. For example, one or morebase station antennas or antenna arrays may be co-located at an antennaassembly, such as an antenna tower. In some cases, antennas or antennaarrays associated with a base station 105 may be located in diversegeographic locations. A base station 105 may have an antenna array witha number of rows and columns of antenna ports that the base station 105may use to support beamforming of communications with a UE 115.Likewise, a UE 115 may have one or more antenna arrays that may supportvarious MIMO or beamforming operations.

In some cases, wireless communications system 100 may be a packet-basednetwork that operate according to a layered protocol stack. In the userplane, communications at the bearer or Packet Data Convergence Protocol(PDCP) layer may be IP-based. A Radio Link Control (RLC) layer mayperform packet segmentation and reassembly to communicate over logicalchannels. A Medium Access Control (MAC) layer may perform priorityhandling and multiplexing of logical channels into transport channels.The MAC layer may also use hybrid automatic repeat request (HARD) toprovide retransmission at the MAC layer to improve link efficiency. Inthe control plane, the Radio Resource Control (RRC) protocol layer mayprovide establishment, configuration, and maintenance of an RRCconnection between a UE 115 and a base station 105 or core network 130supporting radio bearers for user plane data. At the Physical layer,transport channels may be mapped to physical channels.

In some cases, UEs 115 and base stations 105 may support retransmissionsof data to increase the likelihood that data is received successfully.HARQ feedback is one technique of increasing the likelihood that data isreceived correctly over a communication link 125. HARQ may include acombination of error detection (e.g., using a cyclic redundancy check(CRC)), forward error correction (FEC), and retransmission (e.g.,automatic repeat request (ARQ)). HARQ may improve throughput at the MAClayer in poor radio conditions (e.g., signal-to-noise conditions). Insome cases, a wireless device may support same-slot HARQ feedback, wherethe device may provide HARQ feedback in a specific slot for datareceived in a previous symbol in the slot. In other cases, the devicemay provide HARQ feedback in a subsequent slot, or according to someother time interval.

Time intervals in LTE or NR may be expressed in multiples of a basictime unit, which may, for example, refer to a sampling period of T_(s)=1/30,720,000 seconds. Time intervals of a communications resource may beorganized according to radio frames each having a duration of 10milliseconds (ms), where the frame period may be expressed asT_(f)=307,200 T_(s). The radio frames may be identified by a systemframe number (SFN) ranging from 0 to 1023. Each frame may include 10subframes numbered from 0 to 9, and each subframe may have a duration of1 ms. A subframe may be further divided into 2 slots each having aduration of 0.5 ms, and each slot may contain 6 or 7 modulation symbolperiods (e.g., depending on the length of the cyclic prefix prepended toeach symbol period). Excluding the cyclic prefix, each symbol period maycontain 2048 sampling periods. In some cases, a subframe may be thesmallest scheduling unit of the wireless communications system 100 andmay be referred to as a transmission time interval (TTI). In othercases, a smallest scheduling unit of the wireless communications system100 may be shorter than a subframe or may be dynamically selected (e.g.,in bursts of shortened TTIs (sTTIs) or in selected component carriersusing sTTIs).

In some wireless communications systems, a slot may further be dividedinto multiple mini-slots containing one or more symbols. In someinstances, a symbol of a mini-slot or a mini-slot may be the smallestunit of scheduling. Each symbol may vary in duration depending on thesubcarrier spacing or frequency band of operation, for example. Further,some wireless communications systems may implement slot aggregation inwhich multiple slots or mini-slots are aggregated together and used forcommunication between a UE 115 and a base station 105.

The term “carrier” refers to a set of radio frequency spectrum resourceshaving a defined physical layer structure for supporting communicationsover a communication link 125. For example, a carrier of a communicationlink 125 may include a portion of a radio frequency spectrum band thatis operated according to physical layer channels for a given radioaccess technology. Each physical layer channel may carry user data,control information, or other signaling. A carrier may be associatedwith a pre-defined frequency channel (e.g., an evolved universal mobiletelecommunication system terrestrial radio access (E-UTRA) absoluteradio frequency channel number (EARFCN)) and may be positioned accordingto a channel raster for discovery by UEs 115. Carriers may be downlinkor uplink (e.g., in an FDD mode), or be configured to carry downlink anduplink communications (e.g., in a TDD mode). In some examples, signalwaveforms transmitted over a carrier may be made up of multiplesub-carriers (e.g., using multi-carrier modulation (MCM) techniques suchas orthogonal frequency division multiplexing (OFDM) or discrete Fouriertransform spread OFDM (DFT-S-OFDM)).

The organizational structure of the carriers may be different fordifferent radio access technologies (e.g., LTE, LTE-A, LTE-A Pro, NR).For example, communications over a carrier may be organized according toTTIs or slots, each of which may include user data as well as controlinformation or signaling to support decoding the user data. A carriermay also include dedicated acquisition signaling (e.g., synchronizationsignals or system information, etc.) and control signaling thatcoordinates operation for the carrier. In some examples (e.g., in acarrier aggregation configuration), a carrier may also have acquisitionsignaling or control signaling that coordinates operations for othercarriers.

Physical channels may be multiplexed on a carrier according to varioustechniques. A physical control channel and a physical data channel maybe multiplexed on a downlink carrier, for example, using time divisionmultiplexing (TDM) techniques, frequency division multiplexing (FDM)techniques, or hybrid TDM-FDM techniques. In some examples, controlinformation transmitted in a physical control channel may be distributedbetween different control regions in a cascaded manner (e.g., between acommon control region or common search space and one or more UE-specificcontrol regions or UE-specific search spaces).

A carrier may be associated with a particular bandwidth of the radiofrequency spectrum, and in some examples the carrier bandwidth may bereferred to as a “system bandwidth” of the carrier or the wirelesscommunications system 100. For example, the carrier bandwidth may be oneof a number of predetermined bandwidths for carriers of a particularradio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz). Insome examples, each served UE 115 may be configured for operating overportions or all of the carrier bandwidth. In other examples, some UEs115 may be configured for operation using a narrowband protocol typethat is associated with a predefined portion or range (e.g., set ofsubcarriers or RBs) within a carrier (e.g., “in-band” deployment of anarrowband protocol type).

In a system employing MCM techniques, a resource element may consist ofone symbol period (e.g., a duration of one modulation symbol) and onesubcarrier, where the symbol period and subcarrier spacing are inverselyrelated. The number of bits carried by each resource element may dependon the modulation scheme (e.g., the order of the modulation scheme).Thus, the more resource elements that a UE 115 receives and the higherthe order of the modulation scheme, the higher the data rate may be forthe UE 115. In MIMO systems, a wireless communications resource mayrefer to a combination of a radio frequency spectrum resource, a timeresource, and a spatial resource (e.g., spatial layers), and the use ofmultiple spatial layers may further increase the data rate forcommunications with a UE 115.

Devices of the wireless communications system 100 (e.g., base stations105 or UEs 115) may have a hardware configuration that supportscommunications over a particular carrier bandwidth or may beconfigurable to support communications over one of a set of carrierbandwidths. In some examples, the wireless communications system 100 mayinclude base stations 105 and/or UEs 115 that support simultaneouscommunications via carriers associated with more than one differentcarrier bandwidth.

Wireless communications system 100 may support communication with a UE115 on multiple cells or carriers, a feature which may be referred to ascarrier aggregation or multi-carrier operation. A UE 115 may beconfigured with multiple downlink component carriers and one or moreuplink component carriers according to a carrier aggregationconfiguration. Carrier aggregation may be used with both FDD and TDDcomponent carriers.

In some cases, wireless communications system 100 may utilize enhancedcomponent carriers (eCCs). An eCC may be characterized by one or morefeatures including wider carrier or frequency channel bandwidth, shortersymbol duration, shorter TTI duration, or modified control channelconfiguration. In some cases, an eCC may be associated with a carrieraggregation configuration or a dual connectivity configuration (e.g.,when multiple serving cells have a suboptimal or non-ideal backhaullink). An eCC may also be configured for use in unlicensed spectrum orshared spectrum (e.g., where more than one operator is allowed to usethe spectrum). An eCC characterized by wide carrier bandwidth mayinclude one or more segments that may be utilized by UEs 115 that arenot capable of monitoring the whole carrier bandwidth or are otherwiseconfigured to use a limited carrier bandwidth (e.g., to conserve power).

In some cases, an eCC may utilize a different symbol duration than othercomponent carriers, which may include use of a reduced symbol durationas compared with symbol durations of the other component carriers. Ashorter symbol duration may be associated with increased spacing betweenadjacent subcarriers. A device, such as a UE 115 or base station 105,utilizing eCCs may transmit wideband signals (e.g., according tofrequency channel or carrier bandwidths of 20, 40, 60, 80 MHz, etc.) atreduced symbol durations (e.g., 16.67 microseconds). A TTI in eCC mayconsist of one or multiple symbol periods. In some cases, the TTIduration (that is, the number of symbol periods in a TTI) may bevariable.

Wireless communications system 100 may be an NR system that may utilizeany combination of licensed, shared, and unlicensed spectrum bands,among others. The flexibility of eCC symbol duration and subcarrierspacing may allow for the use of eCC across multiple spectrums. In someexamples, NR shared spectrum may increase spectrum utilization andspectral efficiency, specifically through dynamic vertical (e.g., acrossthe frequency domain) and horizontal (e.g., across the time domain)sharing of resources.

In some cases, base station 105 may transmit a new MAC-CE or DCI formatthat may be used to change the BFD-RS at UE 115 to avoid reconfigurationdelays and reduce signaling overhead (e.g., RRC signaling) in the system100. For instance, when the QCL of antenna ports at the UE 115 need tobe updated, the QCL of periodic CSI-RS may be dynamically updated at UE115 by the MAC-CE or DCI from base station 105, at least when theperiodic CSI-RS is for BFD-RS. Thus, the QCL of the original BFD-RS maybe quickly updated without the need of a large number of periodicCSI-RS. In another example, a semi-persistent CSI-RS or aperiodic CSI-RSmay act as a BFD-RS.

In another example, an enhanced update procedure for path loss referencesignal may be used to change the path loss reference signal dynamicallyat UE 115 using MAC-CE or DCI transmitted form base station 105. In somecases, the path loss reference signal parameters updated via MAC-CE orDCI from base station 105 may overwrite the previously RRC configuredpath loss reference signal parameters from base station 105. In anotherexample, if the path loss reference signal is not configured at UE 115,then the path loss reference signal by default may be the spatialrelation reference signal of the corresponding uplink beam for UE 115.

FIG. 2 illustrates an example of a wireless communications system 200that supports techniques for updating reference signals in accordancewith aspects of the present disclosure. In some examples, wirelesscommunications system 200 may implement aspects of wirelesscommunications system 100. In some examples, the wireless communicationssystem 200 may include UE 115-a and base station 105-a, which may beexamples of a UE 115 and base station 105, respectively, described withreference to FIG. 1.

In wireless communications system 200, reference signal 215 may includea periodic CSI-RS that may be used as a BFD-RS, and control message 220may include a MAC-CE or DCI. In some cases, an RRC reconfiguration maybe required when a TCI state for periodic CSI-RS changes. The RRCreconfiguration may update the TCI state ID and a QCL channel stateinformation reference signal 215 (e.g., CSI-RS) parameter (e.g., QCLtype and/or QCL source). In some cases, BFD-RS may be periodicallytransmitted, and may be explicitly configured by RRC signaling orimplicitly configured via a TCI state of a monitored CORESET. In someexamples, the BFD-RSs may include a periodic CSI-RS and an SSB.

In beam failure recovery, when the QCL of a monitored CORESET changesfor UE 115-a, a control message 220 (e.g., a new MAC-CE or DCI format)may be used to update the reference signal 215 parameters (e.g., BFD-RSparameters) to avoid reconfiguration latency and reduce signalingoverhead in the system. For example, the QCL of periodic CSI-RS may bedynamically updated by control message 220 (e.g., MAC-CE or DCI), atleast when the reference signal 215 is periodic CSI-RS is for BFD-RS.Thus, the QCL of the original reference signal 215 (e.g., BFD-RS) may bequickly updated without the need of a large number of periodic CSI-RS.In another example, reference signal 215 may be a semi-persistent oraperiodic reference signal. For example, a semi-persistent or aperiodicreference signal 215 (e.g., CSI-RS) may act as a BFD-RS, and if thesemi-persistent CSI-RS or aperiodic CSI-RS are explicitly configured asBFD-RS, their QCL may be quickly updated by control message 220 (e.g.,MAC-CE or DCI).

In some systems, a reference signal 215 (e.g., path loss referencesignal) for power control may be RRC configured. For example, referencesignal 215 (e.g., path loss reference signal) may be RRC configured perphysical uplink control channel (PUCCH) spatial relation for PUCCH powercontrol, however, this may be an inefficient update methodology and maylead to latency concerns. For PUSCH power control, reference signal 215(e.g., path loss reference signal) may be RRC configured per SRI. ForSRS power control, reference signal 215 (e.g., path loss referencesignal) may be RRC configured per SRS resource set for SRS powercontrol. When a change of the reference signal 215 (e.g., path lossreference signal) occurs in uplink power control, an enhanced updateprocedure for reference signal 215 (e.g., path loss reference signal)may be used to overcome the previous deficiencies of RRCreconfiguration. For example, reference signal 215 (e.g., path lossreference signal) may be updated dynamically by control message 220(e.g., MAC-CE or DCI) such that the reference signal 215 (e.g., pathloss reference signal) may overwrite the previously RRC configuredreference signal 215 (e.g., path loss reference signal). Referencesignal 215 (e.g., path loss reference signal) may be a semi-persistentor aperiodic reference signal (e.g., SRS).

In another example, if a path loss reference signal is not configured,then the path loss reference signal by default may be reference signal215 (e.g., spatial relation reference signal) of the correspondinguplink beam. Specifically, if the path loss reference signal is notconfigured in the PUCCH spatial relation for PUCCH power control, thenthe path loss reference signal may be reference signal 215 (e.g.,spatial relation reference signal) in the spatial relation of thecorresponding PUCCH resource. If a path loss reference signal is notconfigured per SRI for PUSCH power control, then the path loss referencesignal may be reference signal 215 (e.g., the spatial reference signal)in the spatial relation of the SRS resource indicated by SRI.

FIG. 3 illustrates an example of a process flow 300 that supportstechniques for updating reference signals in accordance with aspects ofthe present disclosure. In some examples, process flow 300 may implementaspects of wireless communications system 100. Process flow 300 may beimplemented by a base station 105-b and UE 115-b, which may be examplesof a UE 115 and base station 105, respectively, described with referenceto FIG. 1. Alternative examples of the following may be implemented,where some steps are performed in a different order than described orare not performed at all. In some cases, steps may include additionalfeatures not mentioned below, or further steps may be added.

At 305, base station 105-b may determine a configuration of a firstquasi co-location parameter associated with a control resource set and areference signal. In some cases, the reference signal may include one ormore of a beam failure detection reference signal, a periodic CSI-RS, ora time/frequency tracking reference signal.

In some examples, base station 105-b may select a periodic CSI-RS as thereference signal, wherein the configuration indicates the periodicCSI-RS is for beam failure detection. In another example, base station105-b may select one or more of a semi-persistent CSI-RS or an aperiodicCSI-RS as the reference signal, wherein the configuration indicates thatone or more of the semi-persistent CSI-RS or the aperiodic CSI-RS is forbeam failure detection.

At 310, base station 105-b may optionally transmit a radio resourcecontrol message comprising the configuration of the reference signal,wherein the first quasi co-location parameter is indicated by atransmission configuration indicator state identifier within the radioresource control message.

At 315, UE 115-b may identify a configuration of a first quasico-location parameter associated with a control resource set and areference signal.

In some examples, UE 115-b may determine that the reference signalincludes a periodic CSI-RS for beam failure detection or that thereference signal includes one or more of a semi-persistent CSI-RS or anaperiodic CSI-RS for beam failure detection. The configuration mayindicate that the reference signal comprises the semi-persistent CSI-RSor the aperiodic CSI-RS for beam failure detection.

At 320, base station 105-b may determine that the first quasico-location parameter associated with the control resource set haschanged to a second quasi co-location parameter different from the firstquasi co-location parameter.

At 325, base station 105-b may identify an updated configuration of thereference signal based on the first quasi co-location parameterassociated with the control resource set changing, the updatedconfiguration configuring the reference signal with the second quasico-location parameter.

At 330, base station 105-b may transmit, via one or more of MAC-CEs orDCI, the updated configuration of the reference signal. For instance, aformat of the downlink control information may indicate the referencesignal being configured with the second quasi co-location parameter.

In some cases, base station 105-b may then transmit the reference signalin accordance with the updated configuration, and UE 115-b may monitorfor the reference signal based at least in part on the second quasico-location parameter.

FIG. 4 illustrates an example of a process flow 400 that supportstechniques for updating reference signals in accordance with aspects ofthe present disclosure. In some examples, process flow 400 may implementaspects of wireless communications system 100. Process flow 400 may beimplemented by a base station 105-c and UE 115-c, which may be examplesof a UE 115 and base station 105, respectively, described with referenceto FIG. 1. Alternative examples of the following may be implemented,where some steps are performed in a different order than described orare not performed at all. In some cases, steps may include additionalfeatures not mentioned below, or further steps may be added.

At 405, base station 105-c may transmit, to UE 115-c, a first messagethat indicates a first set of reference signal resources configured fora path loss reference signal. In some cases, the first message mayinclude an RRC message for uplink power control. The uplink powercontrol may be one of more of physical uplink control channel powercontrol, physical uplink shared channel power control, or SRS powercontrol.

At 410, base station 105-c may determine that the first set of referencesignal resources indicated at 405 has changed to a second set ofreference signal resources.

At 415, base station 105-c may transmit, to UE 115-c, a second messagethat indicates the second set of reference signal resources configuredfor the path loss reference signal based on the determination of thefirst set of reference signal resources changing at 410. The secondmessage may include one or more of a MAC-CE or DCI.

At 420, UE 115-c may optionally overwrite the first set of referencesignal resources received at 405 with the second set of reference signalresources based on receiving the second message at 415.

At 425, UE 115-c may optionally estimate a path loss for an uplinkbandwidth part based on the second set of reference signal resourcesassociated with the path loss reference signal. In some examples, thepath loss reference signal may include one or more of a CSI-RS or anSSB.

FIG. 5 illustrates an example of a process flow 500 that supportstechniques for updating reference signals in accordance with aspects ofthe present disclosure. In some examples, process flow 500 may implementaspects of wireless communications system 100. Process flow 500 may beimplemented by a base station 105-d and UE 115-d, which may be examplesof a UE 115 and base station 105, respectively, described with referenceto FIG. 1. Alternative examples of the following may be implemented,where some steps are performed in a different order than described orare not performed at all. In some cases, steps may include additionalfeatures not mentioned below, or further steps may be added.

At 505, the UE 115-d may receive a message from the base station 105-d.The message may indicate a spatial relation reference signal associatedwith an uplink beam. The spatial relation reference signal maycorrespond to a set of physical uplink control channel resources. Insome examples, the spatial relation reference signal may include one ormore of a synchronization signal block, a CSI-RS, or an SRS.

At 510, the UE 115-d may determine whether a path loss reference signalcorresponding to the uplink beam is configured.

At 515, the UE 115-d may optionally determine that the spatial relationreference signal includes the path loss reference signal based on thedetermination that the path loss reference signal is not configured. Thepath loss estimation may be for uplink power control. The uplink powercontrol may include one or more of physical uplink control channel powercontrol, physical uplink shared channel power control, or SRS powercontrol.

At 520, the base station 105-d may determine that a path loss referencesignal corresponding to the uplink beam may not be configured. Thespatial relation reference signal may be used for path loss estimationbased on the determination.

At 525, the base station 105-d may optionally transmit the spatialrelation reference signal. In some cases, the spatial relation referencesignal may correspond to a set of SRS resources indicated by an SRSresource indicator.

At 530, the UE 115-d may monitor the spatial relation reference signalfor path loss estimation based on a determination that the path lossreference signal is not configured.

FIG. 6 illustrates an example of an architecture 600 that supportstechniques for updating reference signals in accordance with aspects ofthe present disclosure. In some examples, Architecture 600 may implementaspects of wireless communications system 100 and or 200. In some cases,architecture 600 may be an example of a transmitting device (e.g., afirst wireless device, such as a UE 115 or base station 105) and/or areceiving device (e.g., a second wireless device, such as a UE 115 orbase station 105) as described herein.

FIG. 6 illustrates example hardware components of a wireless device inaccordance with one or more aspects of the disclosure. The illustratedcomponents may include those that may be used for antenna elementselection and/or for beamforming for transmission of wireless signals.There are numerous architectures for antenna element selection andimplementing phase shifting, only one example of which is illustratedhere. The architecture 600 includes a modem (modulator/demodulator) 602,a digital to analog converter (DAC) 604, a first mixer 606, a secondmixer 608, and a splitter 610. The architecture 600 also includes aplurality of first amplifiers 612, a plurality of phase shifters 614, aplurality of second amplifiers 616, and an antenna array 618 thatincludes a plurality of antenna elements 620. Transmission lines orother waveguides, wires, traces, or the like are shown connecting thevarious components to illustrate how signals to be transmitted maytravel between components. Boxes 622, 624, 626, and 628 indicate regionsin the architecture 600 in which different types of signals travel orare processed. Specifically, box 622 indicates a region in which digitalbaseband signals travel or are processed, box 624 indicates a region inwhich analog baseband signals travel or are processed, box 626 indicatesa region in which analog intermediate frequency (IF) signals travel orare processed, and box 628 indicates a region in which analog radiofrequency (RF) signals travel or are processed. The architecture alsoincludes a local oscillator A 630, a local oscillator B 632, and acommunications manager 634.

Each of the antenna elements 620 may include one or more sub-elements(not shown) for radiating or receiving RF signals. For example, a singleantenna element 620 may include a first sub-element cross-polarized witha second sub-element that can be used to independently transmitcross-polarized signals. The antenna elements 620 may include patchantennas or other types of antennas arranged in a linear, twodimensional, or other pattern. A spacing between antenna elements 620may be such that signals with a desired wavelength transmittedseparately by the antenna elements 620 may interact or interfere (e.g.,to form a desired beam). For example, given an expected range ofwavelengths or frequencies, the spacing may provide a quarterwavelength, half wavelength, or other fraction of a wavelength ofspacing between neighboring antenna elements 620 to allow forinteraction or interference of signals transmitted by the separateantenna elements 620 within that expected range.

The modem 602 processes and generates digital baseband signals and mayalso control operation of the DAC 604, first and second mixers 606, 608,splitter 610, first amplifiers 612, phase shifters 614, and/or thesecond amplifiers 616 to transmit signals via one or more or all of theantenna elements 620. The modem 602 may process signals and controloperation in accordance with a communication standard such as a wirelessstandard discussed herein. The DAC 604 may convert digital basebandsignals received from the modem 602 (and that are to be transmitted)into analog baseband signals. The first mixer 606 upconverts analogbaseband signals to analog IF signals within an IF using a localoscillator A 630. For example, the first mixer 606 may mix the signalswith an oscillating signal generated by the local oscillator A 630 to“move” the baseband analog signals to the IF. In some cases someprocessing or filtering (not shown) may take place at the IF. The secondmixer 608 upconverts the analog IF signals to analog RF signals usingthe local oscillator B 632. Similarly to the first mixer, the secondmixer 608 may mix the signals with an oscillating signal generated bythe local oscillator B 632 to “move” the IF analog signals to the RF, orthe frequency at which signals will be transmitted or received. Themodem 602 and/or the communications manager 634 may adjust the frequencyof local oscillator A 630 and/or the local oscillator B 632 so that adesired IF and/or RF frequency is produced and used to facilitateprocessing and transmission of a signal within a desired bandwidth.

In the illustrated architecture 600, signals upconverted by the secondmixer 608 are split or duplicated into multiple signals by the splitter610. The splitter 610 in architecture 600 splits the RF signal into aplurality of identical or nearly identical RF signals, as denoted by itspresence in box 628. In other examples, the split may take place withany type of signal including with baseband digital, baseband analog, orIF analog signals. Each of these signals may correspond to an antennaelement 620 and the signal travels through and is processed byamplifiers 612, 616, phase shifters 614, and/or other elementscorresponding to the respective antenna element 620 to be provided toand transmitted by the corresponding antenna element 620 of the antennaarray 618. In one example, the splitter 610 may be an active splitterthat is connected to a power supply and provides some gain so that RFsignals exiting the splitter 610 are at a power level equal to orgreater than the signal entering the splitter 610. In another example,the splitter 610 is a passive splitter that is not connected to powersupply and the RF signals exiting the splitter 610 may be at a powerlevel lower than the RF signal entering the splitter 610.

After being split by the splitter 610, the resulting RF signals mayenter an amplifier, such as a first amplifier 612, or a phase shifter614 corresponding to an antenna element 620. The first and secondamplifiers 612, 616 are illustrated with dashed lines because one orboth of them might not be necessary in some implementations. In oneimplementation, both the first amplifier 612 and second amplifier 614are present. In another, neither the first amplifier 612 nor the secondamplifier 614 is present. In other implementations, one of the twoamplifiers 612, 614 is present but not the other. By way of example, ifthe splitter 610 is an active splitter, the first amplifier 612 may notbe used. By way of further example, if the phase shifter 614 is anactive phase shifter that can provide a gain, the second amplifier 616might not be used.

The amplifiers 612, 616 may provide a desired level of positive ornegative gain. A positive gain (positive dB) may be used to increase anamplitude of a signal for radiation by a specific antenna element 620. Anegative gain (negative dB) may be used to decrease an amplitude and/orsuppress radiation of the signal by a specific antenna element. Each ofthe amplifiers 612, 616 may be controlled independently (e.g., by themodem 602 or communications manager 634) to provide independent controlof the gain for each antenna element 620. For example, the modem 602and/or the communications manager 634 may have at least one control lineconnected to each of the splitter 610, first amplifiers 612, phaseshifters 614, and/or second amplifiers 616 which may be used toconfigure a gain to provide a desired amount of gain for each componentand thus each antenna element 620.

The phase shifter 614 may provide a configurable phase shift or phaseoffset to a corresponding RF signal to be transmitted. The phase shifter614 could be a passive phase shifter not directly connected to a powersupply. Passive phase shifters might introduce some insertion loss. Thesecond amplifier 616 could boost the signal to compensate for theinsertion loss. The phase shifter 614 could be an active phase shifterconnected to a power supply such that the active phase shifter providessome amount of gain or prevents insertion loss. The settings of each ofthe phase shifters 614 are independent meaning that each can be set toprovide a desired amount of phase shift or the same amount of phaseshift or some other configuration. The modem 602 and/or thecommunications manager 634 may have at least one control line connectedto each of the phase shifters 614 and which may be used to configure thephase shifters 614 to provide a desired amounts of phase shift or phaseoffset between antenna elements 620.

In the illustrated architecture 600, RF signals received by the antennaelements 620 are provided to one or more of first amplifier 656 to boostthe signal strength. The first amplifier 656 may be connected to thesame antenna arrays 618, e.g., for TDD operations. The first amplifier656 may be connected to different antenna arrays 618. The boosted RFsignal is input into one or more of phase shifter 654 to provide aconfigurable phase shift or phase offset for the corresponding receivedRF signal. The phase shifter 654 may be an active phase shifter or apassive phase shifter. The settings of the phase shifters 654 areindependent, meaning that each can be set to provide a desired amount ofphase shift or the same amount of phase shift or some otherconfiguration. The modem 602 and/or the communications manager 634 mayhave at least one control line connected to each of the phase shifters654 and which may be used to configure the phase sifters 654 to providea desired amount of phase shift or phase offset between antenna elements620.

The outputs of the phase shifters 654 may be input to one or more secondamplifiers 652 for signal amplification of the phase shifted received RFsignals. The second amplifiers 652 may be individually configured toprovide a configured amount of gain. The second amplifiers 652 may beindividually configured to provide an amount of gain to ensure that thesignal input to combiner 650 have the same magnitude. The amplifiers 652and/or 656 are illustrated in dashed lines because they might not benecessary in some implementations. In one implementation, both theamplifier 652 and the amplifier 656 are present. In another, neither theamplifier 652 nor the amplifier 656 are present. In otherimplementations, one of the amplifiers 652, 656 is present but not theother.

In the illustrated architecture 600, signals output by the phaseshifters 654 (via the amplifiers 652 when present) are combined incombiner 650. The combiner 650 in architecture combines the RF signalinto a signal, as denoted by its presence in box 628. The combiner 650may be a passive combiner, e.g., not connected to a power source, whichmay result in some insertion loss. The combiner 650 may be an activecombiner, e.g., connected to a power source, which may result in somesignal gain. When combiner 650 is an active combiner, it may provide adifferent (e.g., configurable) amount of gain for each input signal sothat the input signals have the same magnitude when they are combined.When combiner 650 is an active combiner, it may not need the secondamplifier 652 because the active combiner may provide the signalamplification.

The output of the combiner 650 is input into mixers 648 and 646. Mixers648 and 646 generally down convert the received RF signal using inputsfrom local oscillators 672 and 670, respectively, to create intermediateor baseband signals that carry the encoded and modulated information.The output of the mixers 648 and 646 are input into an analog-to-digitalconverter (ADC) 644 for conversion to analog signals. The analog signalsoutput from ADC 644 is input to modem 602 for baseband processing, e.g.,decoding, de-interleaving, etc.

The architecture 600 is given by way of example to illustrate anarchitecture for transmitting and/or receiving signals. It will beunderstood that the architecture 600 and/or each portion of thearchitecture 600 may be repeated multiple times within an architectureto accommodate or provide an arbitrary number of RF chains, antennaelements, and/or antenna panels. Furthermore, numerous alternatearchitectures are possible and contemplated. For example, although asingle antenna array 618 is shown, two, three, or more antenna arraysmay be included each with one or more of their own correspondingamplifiers, phase shifters, splitters, mixers, DACs, ADCs, and/ormodems. For example, a single UE 115 may include two, four, or moreantenna arrays for transmitting or receiving signals at differentphysical locations on the UE 115 or in different directions.

Further, mixers, splitters, amplifiers, phase shifters and othercomponents may be located in different signal type areas (e.g.,different ones of the boxes 622, 624, 626, 628) in different implementedarchitectures. For example, a split of the signal to be transmitted intoa plurality of signals may take place at the analog RF, analog IF,analog baseband, or digital baseband frequencies in different examples.Similarly, amplification, and/or phase shifts may also take place atdifferent frequencies. For example, in some contemplatedimplementations, one or more of the splitter 610, amplifiers 612, 616,or phase shifters 614 may be located between the DAC 604 and the firstmixer 606 or between the first mixer 606 and the second mixer 608. Inone example, the functions of one or more of the components may becombined into one component. For example, the phase shifters 614 mayperform amplification to include or replace the first and/or or secondamplifiers 612, 616. By way of another example, the second mixer 608 mayimplement a phase shift to obviate the need for a separate phase shifter614. This technique may sometimes be called local oscillator (LO) phaseshifting. In one implementation of this configuration, there may be aplurality of IF to RF mixers (e.g., for each antenna element chain)within the second mixer 608 and the local oscillator B 632 would supplydifferent local oscillator signals (with different phase offsets) toeach IF to RF mixer.

The modem 602 and/or the communications manager 634 may control one ormore of the other components 604-472 to select one or more antennaelements 620 and/or to form beams for transmission of one or moresignals. For example, the antenna elements 620 may be individuallyselected or deselected for transmission of a signal (or signals) bycontrolling an amplitude of one or more corresponding amplifiers, suchas the first amplifiers 612 and/or the second amplifiers 616.Beamforming includes generation of a beam using a plurality of signalson different antenna elements where one or more or all of the pluralitysignals are shifted in phase relative to each other. The formed beam maycarry physical or higher layer reference signals or information. As eachsignal of the plurality of signals is radiated from a respective antennaelement 620, the radiated signals interact, interfere (constructive anddestructive interference), and amplify each other to form a resultingbeam. The shape (such as the amplitude, width, and/or presence of sidelobes) and the direction (such as an angle of the beam relative to asurface of the antenna array 618) can be dynamically controlled bymodifying the phase shifts or phase offsets imparted by the phaseshifters 614 and amplitudes imparted by the amplifiers 612, 616 of theplurality of signals relative to each other.

In some examples, the communications manager 634 may, when architecture600 is configured as a receiving device, identify a configuration of afirst QCL parameter associated with a control resource set and areference signal. The communications manager 634 may receive, via one ormore of a MAC-CE or DCI, an updated configuration for the referencesignal based on the first QCL parameter associated with the controlresource set changing. In such cases, the updated configuration mayindicate that a second QCL parameter is configured for the referencesignal. In another example, the communications manager 634 may receive afirst message that indicates a first set of reference signal resourcesconfigured for a path loss reference signal. The communications manager634 may also receive, based on the first set of reference signalresources changing, a second message that indicates a second set ofreference signal resources configured for the path loss referencesignal, where the second message includes one or more of a MAC-CE orDCI. In some cases, the communications manager 634 may receive a messageindicating a spatial relation reference signal associated with an uplinkbeam. The communications manager 634 may determine whether a path lossreference signal corresponding to the uplink beam is configured.Further, the communications manager 634 may monitor the spatial relationreference signal for path loss estimation based on a determination thatthe path loss reference signal is not configured.

Additionally or alternatively, when architecture 600 is configured as atransmitting device, the communications manager 634 may determine aconfiguration of a first QCL parameter associated with a controlresource set and a reference signal. In some cases, communicationsmanager 634 may determine that the first QCL parameter associated withthe control resource set has changed to a second QCL parameter differentfrom the first QCL parameter. The communications manager 634 mayidentify an updated configuration of the reference signal based on thefirst QCL parameter associated with the control resource set changing,where the updated configuration configures the reference signal with thesecond QCL parameter. The communications manager 634 may transmit, viaone or more of a MAC-CE or DCI, the updated configuration of thereference signal.

In some examples, the communications manager 634 may transmit a firstmessage that indicates a first set of reference signal resourcesconfigured for a path loss reference signal. the communications manager634 may determine that the first set of reference signal resources haschanged to a second set of reference signal resources, and transmit,based on the first set of reference signal resources changing, a secondmessage that indicates the second set of reference signal resourcesconfigured for the path loss reference signal. In such cases, the secondmessage may include one or more of a MAC-CE or DCI. In some aspects, thecommunications manager 634 may transmit a message indicating a spatialrelation reference signal associated with an uplink beam. Thecommunications manager 634 may determine that a path loss referencesignal corresponding to the uplink beam is not configured, where thespatial relation reference signal is used for path loss estimation basedon the determination.

The communications manager 634 may be located partially or fully withinone or more other components of the architecture 600. For example, thecommunications manager 634 may be located within the modem 602 in atleast one implementation.

FIG. 7 shows a block diagram 700 of a device 705 that supportstechniques for updating reference signals in accordance with aspects ofthe present disclosure. The device 705 may be an example of aspects of aUE 115 as described herein. The device 705 may include a receiver 710, acommunications manager 715, and a transmitter 720. The device 705 mayalso include a processor. Each of these components may be incommunication with one another (e.g., via one or more buses).

The receiver 710 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to techniquesfor updating reference signals, etc.). Information may be passed on toother components of the device 705. The receiver 710 may be an exampleof aspects of the transceiver 1020 described with reference to FIG. 10.The receiver 710 may utilize a single antenna or a set of antennas.

The communications manager 715 may identify a configuration of a firstQCL parameter associated with a control resource set and a referencesignal and receive, via one or more of a MAC-CE or DCI, an updatedconfiguration for the reference signal based on the first QCL parameterassociated with the control resource set changing, the updatedconfiguration indicating that a second QCL parameter is configured forthe reference signal.

The communications manager 715 may also receive a first message thatindicates a first set of reference signal resources configured for apath loss reference signal and receive, based on the first set ofreference signal resources changing, a second message that indicates asecond set of reference signal resources configured for the path lossreference signal, where the second message includes one or more of aMAC-CE or DCI. The communications manager 715 may also receive a messageindicating a spatial relation reference signal associated with an uplinkbeam, determine whether a path loss reference signal corresponding tothe uplink beam is configured, and monitor the spatial relationreference signal for path loss estimation based on a determination thatthe path loss reference signal is not configured. The communicationsmanager 715 may be an example of aspects of the communications manager634 and/or the communications manager 1010 described herein.

The communications manager 715, or its sub-components, may beimplemented in hardware, code (e.g., software or firmware) executed by aprocessor, or any combination thereof. If implemented in code executedby a processor, the functions of the communications manager 715, or itssub-components may be executed by a general-purpose processor, a digitalsignal processor (DSP), an application-specific integrated circuit(ASIC), a field programmable gate array (FPGA) or other programmablelogic device, discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed in the present disclosure.

The communications manager 715, or its sub-components, may be physicallylocated at various positions, including being distributed such thatportions of functions are implemented at different physical locations byone or more physical components. In some examples, the communicationsmanager 715, or its sub-components, may be a separate and distinctcomponent in accordance with various aspects of the present disclosure.In some examples, the communications manager 715, or its sub-components,may be combined with one or more other hardware components, includingbut not limited to an input/output (I/O) component, a transceiver, anetwork server, another computing device, one or more other componentsdescribed in the present disclosure, or a combination thereof inaccordance with various aspects of the present disclosure.

The transmitter 720 may transmit signals generated by other componentsof the device 705. In some examples, the transmitter 720 may becollocated with a receiver 710 in a transceiver module. For example, thetransmitter 720 may be an example of aspects of the transceiver 1020described with reference to FIG. 10. The transmitter 720 may utilize asingle antenna or a set of antennas.

FIG. 8 shows a block diagram 800 of a device 805 that supportstechniques for updating reference signals in accordance with aspects ofthe present disclosure. The device 805 may be an example of aspects of adevice 705, or a UE 115 as described herein. The device 805 may includea receiver 810, a communications manager 815, and a transmitter 840. Thedevice 805 may also include a processor. Each of these components may bein communication with one another (e.g., via one or more buses).

The receiver 810 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to techniquesfor updating reference signals, etc.). Information may be passed on toother components of the device 805. The receiver 810 may be an exampleof aspects of the transceiver 1020 described with reference to FIG. 10.The receiver 810 may utilize a single antenna or a set of antennas.

The communications manager 815 may be an example of aspects of thecommunications manager 715 as described herein. The communicationsmanager 815 may include a QCL manager 820, a UE configuration component825, a reference signal manager 830, and a monitoring component 835. Thecommunications manager 815 may be an example of aspects of thecommunications manager 1010 described herein.

The QCL manager 820 may identify a configuration of a first QCLparameter associated with a control resource set and a reference signal.The UE configuration component 825 may receive, via one or more of aMAC-CE or DCI, an updated configuration for the reference signal basedon the first QCL parameter associated with the control resource setchanging, the updated configuration indicating that a second QCLparameter is configured for the reference signal.

The reference signal manager 830 may receive a first message thatindicates a first set of reference signal resources configured for apath loss reference signal. The UE configuration component 825 mayreceive, based on the first set of reference signal resources changing,a second message that indicates a second set of reference signalresources configured for the path loss reference signal, where thesecond message includes one or more of a MAC-CE or DCI.

The reference signal manager 830 may receive a message indicating aspatial relation reference signal associated with an uplink beam. The UEconfiguration component 825 may determine whether a path loss referencesignal corresponding to the uplink beam is configured. The monitoringcomponent 835 may monitor the spatial relation reference signal for pathloss estimation based on a determination that the path loss referencesignal is not configured.

The transmitter 840 may transmit signals generated by other componentsof the device 805. In some examples, the transmitter 840 may becollocated with a receiver 810 in a transceiver module. For example, thetransmitter 840 may be an example of aspects of the transceiver 1020described with reference to FIG. 10. The transmitter 840 may utilize asingle antenna or a set of antennas.

FIG. 9 shows a block diagram 900 of a communications manager 905 thatsupports techniques for updating reference signals in accordance withaspects of the present disclosure. The communications manager 905 may bean example of aspects of a communications manager 715, a communicationsmanager 815, or a communications manager 1010 described herein. Thecommunications manager 905 may include a QCL manager 910, a UEconfiguration component 915, a reference signal manager 920, amonitoring component 925, and a path loss component 930. Each of thesemodules may communicate, directly or indirectly, with one another (e.g.,via one or more buses).

The QCL manager 910 may identify a configuration of a first QCLparameter associated with a control resource set and a reference signal.In some examples, the QCL manager 910 may determine that the first QCLparameter associated with the control resource set has changed to thesecond QCL parameter.

The UE configuration component 915 may receive, via one or more of aMAC-CE or DCI, an updated configuration for the reference signal basedon the first QCL parameter associated with the control resource setchanging, the updated configuration indicating that a second QCLparameter is configured for the reference signal. In some examples,receiving, based on the first set of reference signal resourceschanging, a second message that indicates a second set of referencesignal resources configured for the path loss reference signal, wherethe second message includes one or more of a MAC-CE or DCI.

In some examples, the UE configuration component 915 may determinewhether a path loss reference signal corresponding to the uplink beam isconfigured. In some examples, the UE configuration component 915 mayidentify the updated configuration based on a format of the DCI. In someexamples, the UE configuration component 915 may receive an RRC messageincluding the configuration of the reference signal, where the first QCLparameter is indicated by a transmission configuration indicator stateidentifier within the RRC message. In some cases, the configurationindicates that the reference signal includes the semi-persistent CSI-RSor the aperiodic CSI-RS for beam failure detection.

The reference signal manager 920 may receive a first message thatindicates a first set of reference signal resources configured for apath loss reference signal. In some examples, the reference signalmanager 920 may receive a message indicating a spatial relationreference signal associated with an uplink beam. In some examples,determining that the reference signal includes a periodic CSI-RS forbeam failure detection. In some examples, determining that the referencesignal includes one or more of a semi-persistent CSI-RS or an aperiodicCSI-RS for beam failure detection.

In some examples, the reference signal manager 920 may overwrite thefirst set of reference signal resources with the second set of referencesignal resources based on receiving the second message. In someexamples, determining that the spatial relation reference signalincludes the path loss reference signal based on the determination thatthe path loss reference signal is not configured, where the path lossestimation is for uplink power control.

In some cases, the reference signal includes one or more of a beamfailure detection reference signal, a periodic CSI-RS, or atime/frequency tracking reference signal. In some cases, the firstmessage includes an RRC message for uplink power control. In some cases,the uplink power control includes one of more of physical uplink controlchannel power control, physical uplink shared channel power control, orSRS power control. In some cases, the spatial relation reference signalcorresponds to a set of physical uplink control channel resources.

In some cases, the spatial relation reference signal corresponds to aset of SRS resources indicated by an SRS resource indicator. In somecases, the uplink power control includes one of more of physical uplinkcontrol channel power control, physical uplink shared channel powercontrol, or SRS power control. In some cases, the spatial relationreference signal includes one or more of a synchronization signal block,a CSI-RS, or an SRS.

The monitoring component 925 may monitor the spatial relation referencesignal for path loss estimation based on a determination that the pathloss reference signal is not configured. In some examples, themonitoring component 925 may monitor for the reference signal based onthe second QCL parameter. The path loss component 930 may estimate apath loss for an uplink bandwidth part based on the second set ofreference signal resources associated with the path loss referencesignal. In some cases, the path loss reference signal includes one ormore of a CSI-RS or a synchronization signal block.

FIG. 10 shows a diagram of a system 1000 including a device 1005 thatsupports techniques for updating reference signals in accordance withaspects of the present disclosure. The device 1005 may be an example ofor include the components of device 705, device 805, or a UE 115 asdescribed herein. The device 1005 may include components forbi-directional voice and data communications including components fortransmitting and receiving communications, including a communicationsmanager 1010, an I/O controller 1015, a transceiver 1020, an antenna1025, memory 1030, and a processor 1040. These components may be inelectronic communication via one or more buses (e.g., bus 1045).

The communications manager 1010 may identify a configuration of a firstQCL parameter associated with a control resource set and a referencesignal and receive, via one or more of a MAC-CE or DCI, an updatedconfiguration for the reference signal based on the first QCL parameterassociated with the control resource set changing, the updatedconfiguration indicating that a second QCL parameter is configured forthe reference signal.

The communications manager 1010 may also receive a first message thatindicates a first set of reference signal resources configured for apath loss reference signal and receive, based on the first set ofreference signal resources changing, a second message that indicates asecond set of reference signal resources configured for the path lossreference signal, where the second message includes one or more of aMAC-CE or DCI. The communications manager 1010 may also receive amessage indicating a spatial relation reference signal associated withan uplink beam, determine whether a path loss reference signalcorresponding to the uplink beam is configured, and monitor the spatialrelation reference signal for path loss estimation based on adetermination that the path loss reference signal is not configured.

The I/O controller 1015 may manage input and output signals for thedevice 1005. The I/O controller 1015 may also manage peripherals notintegrated into the device 1005. In some cases, the I/O controller 1015may represent a physical connection or port to an external peripheral.In some cases, the I/O controller 1015 may utilize an operating systemsuch as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, oranother known operating system. In other cases, the I/O controller 1015may represent or interact with a modem, a keyboard, a mouse, atouchscreen, or a similar device. In some cases, the I/O controller 1015may be implemented as part of a processor. In some cases, a user mayinteract with the device 1005 via the I/O controller 1015 or viahardware components controlled by the I/O controller 1015.

The transceiver 1020 may communicate bi-directionally, via one or moreantennas, wired, or wireless links as described above. For example, thetransceiver 1020 may represent a wireless transceiver and maycommunicate bi-directionally with another wireless transceiver. Thetransceiver 1020 may also include a modem to modulate the packets andprovide the modulated packets to the antennas for transmission, and todemodulate packets received from the antennas. In some cases, thewireless device may include a single antenna 1025. However, in somecases the device may have more than one antenna 1025, which may becapable of concurrently transmitting or receiving multiple wirelesstransmissions.

The memory 1030 may include RAM and ROM. The memory 1030 may storecomputer-readable, computer-executable code 1035 including instructionsthat, when executed, cause the processor to perform various functionsdescribed herein. In some cases, the memory 1030 may contain, amongother things, a basic input/output system (BIOS) which may control basichardware or software operation such as the interaction with peripheralcomponents or devices.

The processor 1040 may include an intelligent hardware device, (e.g., ageneral-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, anFPGA, a programmable logic device, a discrete gate or transistor logiccomponent, a discrete hardware component, or any combination thereof).In some cases, the processor 1040 may be configured to operate a memoryarray using a memory controller. In other cases, a memory controller maybe integrated into the processor 1040. The processor 1040 may beconfigured to execute computer-readable instructions stored in a memory(e.g., the memory 1030) to cause the device 1005 to perform variousfunctions (e.g., functions or tasks supporting techniques for updatingreference signals).

The code 1035 may include instructions to implement aspects of thepresent disclosure, including instructions to support wirelesscommunications. The code 1035 may be stored in a non-transitorycomputer-readable medium such as system memory or other type of memory.In some cases, the code 1035 may not be directly executable by theprocessor 1040 but may cause a computer (e.g., when compiled andexecuted) to perform functions described herein.

FIG. 11 shows a block diagram 1100 of a device 1105 that supportstechniques for updating reference signals in accordance with aspects ofthe present disclosure. The device 1105 may be an example of aspects ofa base station 105 as described herein. The device 1105 may include areceiver 1110, a communications manager 1115, and a transmitter 1120.The device 1105 may also include a processor. Each of these componentsmay be in communication with one another (e.g., via one or more buses).

The receiver 1110 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to techniquesfor updating reference signals, etc.). Information may be passed on toother components of the device 1105. The receiver 1110 may be an exampleof aspects of the transceiver 1420 described with reference to FIG. 14.The receiver 1110 may utilize a single antenna or a set of antennas.

The communications manager 1115 may determine a configuration of a firstQCL parameter associated with a control resource set and a referencesignal, determine that the first QCL parameter associated with thecontrol resource set has changed to a second QCL parameter differentfrom the first QCL parameter, identify an updated configuration of thereference signal based on the first QCL parameter associated with thecontrol resource set changing, the updated configuration configuring thereference signal with the second QCL parameter, and transmit, via one ormore of a MAC-CE or DCI, the updated configuration of the referencesignal.

The communications manager 1115 may also transmit a first message thatindicates a first set of reference signal resources configured for apath loss reference signal, determine that the first set of referencesignal resources has changed to a second set of reference signalresources, and transmit, based on the first set of reference signalresources changing, a second message that indicates the second set ofreference signal resources configured for the path loss referencesignal, where the second message includes one or more of a MAC-CE orDCI. The communications manager 1115 may also transmit a messageindicating a spatial relation reference signal associated with an uplinkbeam and determine that a path loss reference signal corresponding tothe uplink beam is not configured, where the spatial relation referencesignal is used for path loss estimation based on the determination. Thecommunications manager 1115 may be an example of aspects of thecommunications manager 634 and/or the communications manager 1410described herein.

The communications manager 1115, or its sub-components, may beimplemented in hardware, code (e.g., software or firmware) executed by aprocessor, or any combination thereof. If implemented in code executedby a processor, the functions of the communications manager 1115, or itssub-components may be executed by a general-purpose processor, a DSP, anapplication-specific integrated circuit (ASIC), a FPGA or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, or any combination thereof designed to perform thefunctions described in the present disclosure.

The communications manager 1115, or its sub-components, may bephysically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations by one or more physical components. In some examples, thecommunications manager 1115, or its sub-components, may be a separateand distinct component in accordance with various aspects of the presentdisclosure. In some examples, the communications manager 1115, or itssub-components, may be combined with one or more other hardwarecomponents, including but not limited to an input/output (I/O)component, a transceiver, a network server, another computing device,one or more other components described in the present disclosure, or acombination thereof in accordance with various aspects of the presentdisclosure.

The transmitter 1120 may transmit signals generated by other componentsof the device 1105. In some examples, the transmitter 1120 may becollocated with a receiver 1110 in a transceiver module. For example,the transmitter 1120 may be an example of aspects of the transceiver1420 described with reference to FIG. 14. The transmitter 1120 mayutilize a single antenna or a set of antennas.

FIG. 12 shows a block diagram 1200 of a device 1205 that supportstechniques for updating reference signals in accordance with aspects ofthe present disclosure. The device 1205 may be an example of aspects ofa device 1105, or a base station 105 as described herein. The device1205 may include a receiver 1210, a communications manager 1215, and atransmitter 1240. The device 1205 may also include a processor. Each ofthese components may be in communication with one another (e.g., via oneor more buses).

The receiver 1210 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to techniquesfor updating reference signals, etc.). Information may be passed on toother components of the device 1205. The receiver 1210 may be an exampleof aspects of the transceiver 1420 described with reference to FIG. 14.The receiver 1210 may utilize a single antenna or a set of antennas.

The communications manager 1215 may be an example of aspects of thecommunications manager 1115 as described herein. The communicationsmanager 1215 may include a QCL configuration manager 1220, a referencesignal configuration manager 1225, a configuration signaling component1230, and a reference signal resource manager 1235. The communicationsmanager 1215 may be an example of aspects of the communications manager1410 described herein.

The QCL configuration manager 1220 may determine a configuration of afirst QCL parameter associated with a control resource set and areference signal and determine that the first QCL parameter associatedwith the control resource set has changed to a second QCL parameterdifferent from the first QCL parameter.

The reference signal configuration manager 1225 may identify an updatedconfiguration of the reference signal based on the first QCL parameterassociated with the control resource set changing, the updatedconfiguration configuring the reference signal with the second QCLparameter. The configuration signaling component 1230 may transmit, viaone or more of a MAC-CE or DCI, the updated configuration of thereference signal.

The reference signal resource manager 1235 may transmit a first messagethat indicates a first set of reference signal resources configured fora path loss reference signal and determine that the first set ofreference signal resources has changed to a second set of referencesignal resources.

The configuration signaling component 1230 may transmit, based on thefirst set of reference signal resources changing, a second message thatindicates the second set of reference signal resources configured forthe path loss reference signal, where the second message includes one ormore of a MAC-CE or DCI.

The configuration signaling component 1230 may transmit a messageindicating a spatial relation reference signal associated with an uplinkbeam. The reference signal configuration manager 1225 may determine thata path loss reference signal corresponding to the uplink beam is notconfigured, where the spatial relation reference signal is used for pathloss estimation based on the determination.

The transmitter 1240 may transmit signals generated by other componentsof the device 1205. In some examples, the transmitter 1240 may becollocated with a receiver 1210 in a transceiver module. For example,the transmitter 1240 may be an example of aspects of the transceiver1420 described with reference to FIG. 14. The transmitter 1240 mayutilize a single antenna or a set of antennas.

FIG. 13 shows a block diagram 1300 of a communications manager 1305 thatsupports techniques for updating reference signals in accordance withaspects of the present disclosure. The communications manager 1305 maybe an example of aspects of a communications manager 1115, acommunications manager 1215, or a communications manager 1410 describedherein. The communications manager 1305 may include a QCL configurationmanager 1310, a reference signal configuration manager 1315, aconfiguration signaling component 1320, a reference signal component1325, and a reference signal resource manager 1330. Each of thesemodules may communicate, directly or indirectly, with one another (e.g.,via one or more buses).

The QCL configuration manager 1310 may determine a configuration of afirst QCL parameter associated with a control resource set and areference signal. In some examples, the QCL configuration manager 1310may determine that the first QCL parameter associated with the controlresource set has changed to a second QCL parameter different from thefirst QCL parameter. In some cases, the reference signal includes one ormore of a beam failure detection reference signal, a periodic CSI-RS, ora time/frequency tracking reference signal.

The reference signal configuration manager 1315 may identify an updatedconfiguration of the reference signal based on the first QCL parameterassociated with the control resource set changing, the updatedconfiguration configuring the reference signal with the second QCLparameter. In some examples, the reference signal configuration manager1315 may determine that a path loss reference signal corresponding tothe uplink beam is not configured, where the spatial relation referencesignal is used for path loss estimation based on the determination.

In some examples, the reference signal configuration manager 1315 mayselect a periodic CSI-RS as the reference signal, where theconfiguration indicates the periodic CSI-RS is for beam failuredetection. In some examples, the reference signal configuration manager1315 may select one or more of a semi-persistent CSI-RS or an aperiodicCSI-RS as the reference signal, where the configuration indicates thatone or more of the semi-persistent CSI-RS or the aperiodic CSI-RS is forbeam failure detection.

The configuration signaling component 1320 may transmit, via one or moreof a MAC-CE or DCI, the updated configuration of the reference signal.In some examples, transmitting, based on the first set of referencesignal resources changing, a second message that indicates the secondset of reference signal resources configured for the path loss referencesignal, where the second message includes one or more of a MAC-CE orDCI.

In some examples, the configuration signaling component 1320 maytransmit a message indicating a spatial relation reference signalassociated with an uplink beam. In some examples, the configurationsignaling component 1320 may transmit an RRC message including theconfiguration of the reference signal, where the first QCL parameter isindicated by a transmission configuration indicator state identifierwithin the RRC message.

In some cases, a format of the DCI indicates the reference signal beingconfigured with the second QCL parameter. In some cases, the spatialrelation reference signal corresponds to a set of physical uplinkcontrol channel resources. In some cases, the spatial relation referencesignal corresponds to a set of SRS resources indicated by an SRSresource indicator.

The reference signal resource manager 1330 may transmit a first messagethat indicates a first set of reference signal resources configured fora path loss reference signal. In some examples, the reference signalresource manager 1330 may determine that the first set of referencesignal resources has changed to a second set of reference signalresources. In some cases, the second set of reference signal resourcesoverwrites the first set of reference signal resources. In some cases,the first message includes an RRC message for uplink power control. Insome cases, the uplink power control includes one of more of physicaluplink control channel power control, physical uplink shared channelpower control, or SRS power control. The reference signal component 1325may transmit the reference signal in accordance with the updatedconfiguration.

FIG. 14 shows a diagram of a system 1400 including a device 1405 thatsupports techniques for updating reference signals in accordance withaspects of the present disclosure. The device 1405 may be an example ofor include the components of device 1105, device 1205, or a base station105 as described herein. The device 1405 may include components forbi-directional voice and data communications including components fortransmitting and receiving communications, including a communicationsmanager 1410, a network communications manager 1415, a transceiver 1420,an antenna 1425, memory 1430, a processor 1440, and an inter-stationcommunications manager 1445. These components may be in electroniccommunication via one or more buses (e.g., bus 1450).

The communications manager 1410 may determine a configuration of a firstQCL parameter associated with a control resource set and a referencesignal, determine that the first QCL parameter associated with thecontrol resource set has changed to a second QCL parameter differentfrom the first QCL parameter, identify an updated configuration of thereference signal based on the first QCL parameter associated with thecontrol resource set changing, the updated configuration configuring thereference signal with the second QCL parameter, and transmit, via one ormore of a MAC-CE or DCI, the updated configuration of the referencesignal.

The communications manager 1410 may also transmit a first message thatindicates a first set of reference signal resources configured for apath loss reference signal, determine that the first set of referencesignal resources has changed to a second set of reference signalresources, and transmit, based on the first set of reference signalresources changing, a second message that indicates the second set ofreference signal resources configured for the path loss referencesignal, where the second message includes one or more of a MAC-CE orDCI. The communications manager 1410 may also transmit a messageindicating a spatial relation reference signal associated with an uplinkbeam and determine that a path loss reference signal corresponding tothe uplink beam is not configured, where the spatial relation referencesignal is used for path loss estimation based on the determination.

The network communications manager 1415 may manage communications withthe core network (e.g., via one or more wired backhaul links). Forexample, the network communications manager 1415 may manage the transferof data communications for client devices, such as one or more UEs 115.

The transceiver 1420 may communicate bi-directionally, via one or moreantennas, wired, or wireless links as described above. For example, thetransceiver 1420 may represent a wireless transceiver and maycommunicate bi-directionally with another wireless transceiver. Thetransceiver 1420 may also include a modem to modulate the packets andprovide the modulated packets to the antennas for transmission, and todemodulate packets received from the antennas. In some cases, thewireless device may include a single antenna 1425. However, in somecases the device may have more than one antenna 1425, which may becapable of concurrently transmitting or receiving multiple wirelesstransmissions.

The memory 1430 may include RAM, ROM, or a combination thereof. Thememory 1430 may store computer-readable code 1435 including instructionsthat, when executed by a processor (e.g., the processor 1440) cause thedevice to perform various functions described herein. In some cases, thememory 1430 may contain, among other things, a BIOS which may controlbasic hardware or software operation such as the interaction withperipheral components or devices.

The processor 1440 may include an intelligent hardware device, (e.g., ageneral-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, anFPGA, a programmable logic device, a discrete gate or transistor logiccomponent, a discrete hardware component, or any combination thereof).In some cases, the processor 1440 may be configured to operate a memoryarray using a memory controller. In some cases, a memory controller maybe integrated into processor 1440. The processor 1440 may be configuredto execute computer-readable instructions stored in a memory (e.g., thememory 1430) to cause the device 1405 to perform various functions(e.g., functions or tasks supporting techniques for updating referencesignals).

The inter-station communications manager 1445 may manage communicationswith other base station 105, and may include a controller or schedulerfor controlling communications with UEs 115 in cooperation with otherbase stations 105. For example, the inter-station communications manager1445 may coordinate scheduling for transmissions to UEs 115 for variousinterference mitigation techniques such as beamforming or jointtransmission. In some examples, the inter-station communications manager1445 may provide an X2 interface within an LTE/LTE-A wirelesscommunication network technology to provide communication between basestations 105.

The code 1435 may include instructions to implement aspects of thepresent disclosure, including instructions to support wirelesscommunications. The code 1435 may be stored in a non-transitorycomputer-readable medium such as system memory or other type of memory.In some cases, the code 1435 may not be directly executable by theprocessor 1440 but may cause a computer (e.g., when compiled andexecuted) to perform functions described herein.

FIG. 15 shows a flowchart illustrating a method 1500 that supportstechniques for updating reference signals in accordance with aspects ofthe present disclosure. The operations of method 1500 may be implementedby a UE 115 or its components as described herein. For example, theoperations of method 1500 may be performed by a communications manageras described with reference to FIGS. 7 through 10. In some examples, aUE may execute a set of instructions to control the functional elementsof the UE to perform the functions described below. Additionally oralternatively, a UE may perform aspects of the functions described belowusing special-purpose hardware.

At 1505, the UE may identify a configuration of a first QCL parameterassociated with a control resource set and a reference signal. Theoperations of 1505 may be performed according to the methods describedherein. In some examples, aspects of the operations of 1505 may beperformed by a QCL manager as described with reference to FIGS. 7through 10.

At 1510, the UE may receive, via one or more of a MAC-CE or DCI, anupdated configuration for the reference signal based on the first QCLparameter associated with the control resource set changing, the updatedconfiguration indicating that a second QCL parameter is configured forthe reference signal. The operations of 1510 may be performed accordingto the methods described herein. In some examples, aspects of theoperations of 1510 may be performed by a UE configuration component asdescribed with reference to FIGS. 7 through 10.

FIG. 16 shows a flowchart illustrating a method 1600 that supportstechniques for updating reference signals in accordance with aspects ofthe present disclosure. The operations of method 1600 may be implementedby a UE 115 or its components as described herein. For example, theoperations of method 1600 may be performed by a communications manageras described with reference to FIGS. 7 through 10. In some examples, aUE may execute a set of instructions to control the functional elementsof the UE to perform the functions described below. Additionally oralternatively, a UE may perform aspects of the functions described belowusing special-purpose hardware.

At 1605, the UE may receive a first message that indicates a first setof reference signal resources configured for a path loss referencesignal. The operations of 1605 may be performed according to the methodsdescribed herein. In some examples, aspects of the operations of 1605may be performed by a reference signal manager as described withreference to FIGS. 7 through 10.

At 1610, the UE may receive, based on the first set of reference signalresources changing, a second message that indicates a second set ofreference signal resources configured for the path loss referencesignal, where the second message includes one or more of a MAC-CE orDCI. The operations of 1610 may be performed according to the methodsdescribed herein. In some examples, aspects of the operations of 1610may be performed by a UE configuration component as described withreference to FIGS. 7 through 10.

FIG. 17 shows a flowchart illustrating a method 1700 that supportstechniques for updating reference signals in accordance with aspects ofthe present disclosure. The operations of method 1700 may be implementedby a UE 115 or its components as described herein. For example, theoperations of method 1700 may be performed by a communications manageras described with reference to FIGS. 7 through 10. In some examples, aUE may execute a set of instructions to control the functional elementsof the UE to perform the functions described below. Additionally oralternatively, a UE may perform aspects of the functions described belowusing special-purpose hardware.

At 1705, the UE may receive a message indicating a spatial relationreference signal associated with an uplink beam. The operations of 1705may be performed according to the methods described herein. In someexamples, aspects of the operations of 1705 may be performed by areference signal manager as described with reference to FIGS. 7 through10.

At 1710, the UE may determine whether a path loss reference signalcorresponding to the uplink beam is configured. The operations of 1710may be performed according to the methods described herein. In someexamples, aspects of the operations of 1710 may be performed by a UEconfiguration component as described with reference to FIGS. 7 through10.

At 1715, the UE may monitor the spatial relation reference signal forpath loss estimation based on a determination that the path lossreference signal is not configured. The operations of 1715 may beperformed according to the methods described herein. In some examples,aspects of the operations of 1715 may be performed by a monitoringcomponent as described with reference to FIGS. 7 through 10.

FIG. 18 shows a flowchart illustrating a method 1800 that supportstechniques for updating reference signals in accordance with aspects ofthe present disclosure. The operations of method 1800 may be implementedby a base station 105 or its components as described herein. Forexample, the operations of method 1800 may be performed by acommunications manager as described with reference to FIGS. 11 through14. In some examples, a base station may execute a set of instructionsto control the functional elements of the base station to perform thefunctions described below. Additionally or alternatively, a base stationmay perform aspects of the functions described below usingspecial-purpose hardware.

At 1805, the base station may determine a configuration of a first QCLparameter associated with a control resource set and a reference signal.The operations of 1805 may be performed according to the methodsdescribed herein. In some examples, aspects of the operations of 1805may be performed by a QCL configuration manager as described withreference to FIGS. 11 through 14.

At 1810, the base station may determine that the first QCL parameterassociated with the control resource set has changed to a second QCLparameter different from the first QCL parameter. The operations of 1810may be performed according to the methods described herein. In someexamples, aspects of the operations of 1810 may be performed by a QCLconfiguration manager as described with reference to FIGS. 11 through14.

At 1815, the base station may identify an updated configuration of thereference signal based on the first QCL parameter associated with thecontrol resource set changing, the updated configuration configuring thereference signal with the second QCL parameter. The operations of 1815may be performed according to the methods described herein. In someexamples, aspects of the operations of 1815 may be performed by areference signal configuration manager as described with reference toFIGS. 11 through 14.

At 1820, the base station may transmit, via one or more of a MAC-CE orDCI, the updated configuration of the reference signal. The operationsof 1820 may be performed according to the methods described herein. Insome examples, aspects of the operations of 1820 may be performed by aconfiguration signaling component as described with reference to FIGS.11 through 14.

FIG. 19 shows a flowchart illustrating a method 1900 that supportstechniques for updating reference signals in accordance with aspects ofthe present disclosure. The operations of method 1900 may be implementedby a base station 105 or its components as described herein. Forexample, the operations of method 1900 may be performed by acommunications manager as described with reference to FIGS. 11 through14. In some examples, a base station may execute a set of instructionsto control the functional elements of the base station to perform thefunctions described below. Additionally or alternatively, a base stationmay perform aspects of the functions described below usingspecial-purpose hardware.

At 1905, the base station may transmit a first message that indicates afirst set of reference signal resources configured for a path lossreference signal. The operations of 1905 may be performed according tothe methods described herein. In some examples, aspects of theoperations of 1905 may be performed by a reference signal resourcemanager as described with reference to FIGS. 11 through 14.

At 1910, the base station may determine that the first set of referencesignal resources has changed to a second set of reference signalresources. The operations of 1910 may be performed according to themethods described herein. In some examples, aspects of the operations of1910 may be performed by a reference signal resource manager asdescribed with reference to FIGS. 11 through 14.

At 1915, the base station may transmit, based on the first set ofreference signal resources changing, a second message that indicates thesecond set of reference signal resources configured for the path lossreference signal, where the second message includes one or more of aMAC-CE or DCI. The operations of 1915 may be performed according to themethods described herein. In some examples, aspects of the operations of1915 may be performed by a configuration signaling component asdescribed with reference to FIGS. 11 through 14.

FIG. 20 shows a flowchart illustrating a method 2000 that supportstechniques for updating reference signals in accordance with aspects ofthe present disclosure. The operations of method 2000 may be implementedby a base station 105 or its components as described herein. Forexample, the operations of method 2000 may be performed by acommunications manager as described with reference to FIGS. 11 through14. In some examples, a base station may execute a set of instructionsto control the functional elements of the base station to perform thefunctions described below. Additionally or alternatively, a base stationmay perform aspects of the functions described below usingspecial-purpose hardware.

At 2005, the base station may transmit a message indicating a spatialrelation reference signal associated with an uplink beam. The operationsof 2005 may be performed according to the methods described herein. Insome examples, aspects of the operations of 2005 may be performed by aconfiguration signaling component as described with reference to FIGS.11 through 14.

At 2010, the base station may determine that a path loss referencesignal corresponding to the uplink beam is not configured, where thespatial relation reference signal is used for path loss estimation basedon the determination. The operations of 2010 may be performed accordingto the methods described herein. In some examples, aspects of theoperations of 2010 may be performed by a reference signal configurationmanager as described with reference to FIGS. 11 through 14.

It should be noted that the methods described herein describe possibleimplementations, and that the operations and the steps may be rearrangedor otherwise modified and that other implementations are possible.Further, aspects from two or more of the methods may be combined.

Aspects of the following examples may be combined with any of theprevious examples or aspects described herein. For instance, example 1is a method for wireless communications that includes: identifying aconfiguration of a first QCL parameter associated with a CORESET and areference signal and receiving, via one or more of a MAC-CE or DCI, anupdated configuration for the reference signal based on the first QCLparameter associated with the CORESET changing, the updatedconfiguration indicating that a second QCL parameter is configured forthe reference signal.

In example 2, the method of example 1 may include determining that thereference signal includes a periodic CSI-RS for beam failure detection.

In example 3, the method of examples 1-2 may include determining thatthe reference signal includes one or more of a semi-persistent CSI-RS oran aperiodic CSI-RS for beam failure detection.

In example 4, the method of examples 1-3 may include the configurationindicating that the reference signal includes the semi-persistent CSI-RSor the aperiodic CSI-RS for beam failure detection.

In example 5, the method of examples 1-4 may include the referencesignal comprising one or more of a BFD-RS, a periodic CSI-RS, or atime/frequency tracking reference signal (TRS).

In example 6, the method of examples 1-5 may include determining thatthe first QCL parameter associated with the CORESET may have changed tothe second QCL parameter.

In example 7, the method of examples 1-6 may include identifying theupdated configuration based on a format of the DCI.

In example 8, the method of examples 1-7 may include monitoring for thereference signal based on the second QCL parameter.

In example 9, the method of examples 1-8 may include receiving an RRCmessage including the configuration of the reference signal, where thefirst QCL parameter may be indicated by a transmission configurationindicator state identifier within the RRC message.

Example 10 is a method for wireless communications that includes:receiving a first message that indicates a first set of reference signalresources configured for a path loss reference signal and receiving,based on the first set of reference signal resources changing, a secondmessage that indicates a second set of reference signal resourcesconfigured for the path loss reference signal, where the second messageincludes one or more of a MAC-CE or DCI.

In example 11, the method of example 10 may include overwriting thefirst set of reference signal resources with the second set of referencesignal resources based on receiving the second message, and estimating apath loss for an uplink bandwidth part based on the second set ofreference signal resources associated with the path loss referencesignal.

In example 12, the method of examples 10-11 may include the firstmessage including an RRC message for uplink power control.

In example 13, the method of examples 10-12 may include the uplink powercontrol including one of more of physical uplink control channel powercontrol, physical uplink shared channel power control, or SRS powercontrol.

In example 14, the method of examples 10-13 may include the SRS powercontrol including an aperiodic SRS.

In example 15, the method of examples 10-13 may include the SRS powercontrol including an aperiodic SRS.

In example 16, the method of examples 10-15 may include the path lossreference signal including one or more of a CSI-RS or an SSB.

Example 17 is a method for wireless communications that includes:receiving a message indicating a spatial relation reference signalassociated with an uplink beam, determining whether a path lossreference signal corresponding to the uplink beam is configured, andmonitoring the spatial relation reference signal for path lossestimation based on a determination that the path loss reference signalis not configured.

In example 18, the method of example 17 may include determining that thespatial relation reference signal includes the path loss referencesignal based on the determination that the path loss reference signalmay be not configured, where the path loss estimation may be for uplinkpower control.

In example 19, the method of examples 17-18 may include the spatialrelation reference signal corresponding to a set of physical uplinkcontrol channel resources.

In example 20, the method of examples 17-19 may include the spatialrelation reference signal corresponding to a set of SRS resourcesindicated by an SRS resource indicator.

In example 21, the method of examples 17-20 may include the uplink powercontrol comprising one of more of physical uplink control channel powercontrol, physical uplink shared channel power control, or SRS powercontrol.

In example 22, the method of examples 17-21 may include the spatialrelation reference signal comprising one or more of an SSB, a CSI-RS, oran SRS.

Example 23 is a method for wireless communications that includes:determining a configuration of a first QCL parameter associated with aCORESET and a reference signal, determining that the first QCL parameterassociated with the CORESET has changed to a second QCL parameterdifferent from the first QCL parameter, identifying an updatedconfiguration of the reference signal based on the first QCL parameterassociated with the CORESET changing, the updated configurationconfiguring the reference signal with the second QCL parameter, andtransmitting, via one or more of a MAC-CE or DCI, the updatedconfiguration of the reference signal.

In example 24, the method of example 23 may include selecting a periodicCSI-RS as the reference signal, where the configuration indicates theperiodic CSI-RS may be for beam failure detection.

In example 25, the method of examples 23-24 may include selecting one ormore of a semi-persistent CSI-RS or an aperiodic CSI-RS as the referencesignal, where the configuration indicates that one or more of thesemi-persistent CSI-RS or the aperiodic CSI-RS may be for beam failuredetection.

In example 26, the method of examples 23-25 may include a format of theDCI indicating the reference signal being configured with the second QCLparameter.

In example 27, the method of examples 23-26 may include the referencesignal comprising one or more of a BFD-RS, a periodic CSI-RS, or atime/frequency tracking reference signal.

In example 28, the method of examples 23-27 may include transmitting thereference signal in accordance with the updated configuration.

In example 29, the method of examples 23-28 may include transmitting anRRC message including the configuration of the reference signal, wherethe first QCL parameter may be indicated by a transmission configurationindicator state identifier within the RRC message.

Example 30 is a method for wireless communications including:transmitting a first message that indicates a first set of referencesignal resources configured for a path loss reference signal,determining that the first set of reference signal resources has changedto a second set of reference signal resources, and transmitting, basedon the first set of reference signal resources changing, a secondmessage that indicates the second set of reference signal resourcesconfigured for the path loss reference signal, where the second messageincludes one or more of a MAC-CE or DCI.

In example 31, the method of example 30 may include the second set ofreference signal resources overwriting the first set of reference signalresources.

In example 32, the method of examples 30-31 may include the firstmessage including an RRC message for uplink power control.

In example 33, the method of examples 30-32 may include the uplink powercontrol comprising one of more of physical uplink control channel powercontrol, physical uplink shared channel power control, or SRS powercontrol.

In example 34, the method of examples 30-33 may include the SRS powercontrol including an aperiodic SRS.

In example 35, the method of examples 30-33 may include the SRS powercontrol including an aperiodic SRS. Example 36 is a method for wirelesscommunications including: transmitting a message indicating a spatialrelation reference signal associated with an uplink beam and determiningthat a path loss reference signal corresponding to the uplink beam isnot configured, where the spatial relation reference signal is used forpath loss estimation based on the determination.

In example 37, the method of example 36 may include the spatial relationreference signal corresponding to a set of physical uplink controlchannel resources.

In example 38, the method of example 36-37 may include the spatialrelation reference signal corresponding to a set of SRS resourcesindicated by an SRS resource indicator.

Example 39 is a system or apparatus including means for implementing amethod or realizing an apparatus as in any of examples 1-38.

Example 40 is a non-transitory computer-readable medium storinginstructions executable by one or more processors to cause the one ormore processors to implement a method as in any of examples 1-38.

Example 41 is a system including one or more processors and memory inelectronic communication with the one or more processors storinginstructions executable by the one or more processors to cause thesystem or apparatus to implement a method as in any of examples 1-38.

Techniques described herein may be used for various wirelesscommunications systems such as code division multiple access (CDMA),time division multiple access (TDMA), frequency division multiple access(FDMA), orthogonal frequency division multiple access (OFDMA), singlecarrier frequency division multiple access (SC-FDMA), and other systems.A CDMA system may implement a radio technology such as CDMA2000,Universal Terrestrial Radio Access (UTRA), etc. CDMA2000 covers IS-2000,IS-95, and IS-856 standards. IS-2000 Releases may be commonly referredto as CDMA2000 1×, 1×, etc. IS-856 (TIA-856) is commonly referred to asCDMA2000 1×EV-DO, High Rate Packet Data (HRPD), etc. UTRA includesWideband CDMA (WCDMA) and other variants of CDMA. A TDMA system mayimplement a radio technology such as Global System for MobileCommunications (GSM).

An OFDMA system may implement a radio technology such as Ultra MobileBroadband (UMB), Evolved UTRA (E-UTRA), Institute of Electrical andElectronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of Universal MobileTelecommunications System (UMTS). LTE, LTE-A, and LTE-A Pro are releasesof UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, LTE-A Pro, NR,and GSM are described in documents from the organization named “3rdGeneration Partnership Project” (3GPP). CDMA2000 and UMB are describedin documents from an organization named “3rd Generation PartnershipProject 2” (3GPP2). The techniques described herein may be used for thesystems and radio technologies mentioned herein as well as other systemsand radio technologies. While aspects of an LTE, LTE-A, LTE-A Pro, or NRsystem may be described for purposes of example, and LTE, LTE-A, LTE-APro, or NR terminology may be used in much of the description, thetechniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro,or NR applications.

A macro cell generally covers a relatively large geographic area (e.g.,several kilometers in radius) and may allow unrestricted access by UEswith service subscriptions with the network provider. A small cell maybe associated with a lower-powered base station, as compared with amacro cell, and a small cell may operate in the same or different (e.g.,licensed, unlicensed, etc.) frequency bands as macro cells. Small cellsmay include pico cells, femto cells, and micro cells according tovarious examples. A pico cell, for example, may cover a small geographicarea and may allow unrestricted access by UEs with service subscriptionswith the network provider. A femto cell may also cover a smallgeographic area (e.g., a home) and may provide restricted access by UEshaving an association with the femto cell (e.g., UEs in a closedsubscriber group (CSG), UEs for users in the home, and the like). An eNBfor a macro cell may be referred to as a macro eNB. An eNB for a smallcell may be referred to as a small cell eNB, a pico eNB, a femto eNB, ora home eNB. An eNB may support one or multiple (e.g., two, three, four,and the like) cells, and may also support communications using one ormultiple component carriers.

The wireless communications systems described herein may supportsynchronous or asynchronous operation. For synchronous operation, thebase stations may have similar frame timing, and transmissions fromdifferent base stations may be approximately aligned in time. Forasynchronous operation, the base stations may have different frametiming, and transmissions from different base stations may not bealigned in time. The techniques described herein may be used for eithersynchronous or asynchronous operations.

Information and signals described herein may be represented using any ofa variety of different technologies and techniques. For example, data,instructions, commands, information, signals, bits, symbols, and chipsthat may be referenced throughout the description may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, or any combination thereof.

The various illustrative blocks and modules described in connection withthe disclosure herein may be implemented or performed with ageneral-purpose processor, a DSP, an ASIC, an FPGA, or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, or any combination thereof designed to perform thefunctions described herein. A general-purpose processor may be amicroprocessor, but in the alternative, the processor may be anyconventional processor, controller, microcontroller, or state machine. Aprocessor may also be implemented as a combination of computing devices(e.g., a combination of a DSP and a microprocessor, multiplemicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration).

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on acomputer-readable medium. Other examples and implementations are withinthe scope of the disclosure and appended claims. For example, due to thenature of software, functions described herein can be implemented usingsoftware executed by a processor, hardware, firmware, hardwiring, orcombinations of any of these. Features implementing functions may alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations.

Computer-readable media includes both non-transitory computer storagemedia and communication media including any medium that facilitatestransfer of a computer program from one place to another. Anon-transitory storage medium may be any available medium that can beaccessed by a general purpose or special purpose computer. By way ofexample, and not limitation, non-transitory computer-readable media mayinclude random-access memory (RAM), read-only memory (ROM), electricallyerasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROMor other optical disk storage, magnetic disk storage or other magneticstorage devices, or any other non-transitory medium that can be used tocarry or store desired program code means in the form of instructions ordata structures and that can be accessed by a general-purpose orspecial-purpose computer, or a general-purpose or special-purposeprocessor. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, include CD, laser disc, optical disc,digital versatile disc (DVD), floppy disk and Blu-ray disc where disksusually reproduce data magnetically, while discs reproduce dataoptically with lasers. Combinations of the above are also includedwithin the scope of computer-readable media.

As used herein, including in the claims, “or” as used in a list of items(e.g., a list of items prefaced by a phrase such as “at least one of” or“one or more of”) indicates an inclusive list such that, for example, alist of at least one of A, B, or C means A or B or C or AB or AC or BCor ABC (i.e., A and B and C). Also, as used herein, the phrase “basedon” shall not be construed as a reference to a closed set of conditions.For example, an exemplary step that is described as “based on conditionA” may be based on both a condition A and a condition B withoutdeparting from the scope of the present disclosure. In other words, asused herein, the phrase “based on” shall be construed in the same manneras the phrase “based at least in part on.”

In the appended figures, similar components or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If just the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label, or othersubsequent reference label.

The description set forth herein, in connection with the appendeddrawings, describes example configurations and does not represent allthe examples that may be implemented or that are within the scope of theclaims. The term “exemplary” used herein means “serving as an example,instance, or illustration,” and not “preferred” or “advantageous overother examples.” The detailed description includes specific details forthe purpose of providing an understanding of the described techniques.These techniques, however, may be practiced without these specificdetails. In some instances, well-known structures and devices are shownin block diagram form in order to avoid obscuring the concepts of thedescribed examples.

The description herein is provided to enable a person skilled in the artto make or use the disclosure. Various modifications to the disclosurewill be readily apparent to those skilled in the art, and the genericprinciples defined herein may be applied to other variations withoutdeparting from the scope of the disclosure. Thus, the disclosure is notlimited to the examples and designs described herein but is to beaccorded the broadest scope consistent with the principles and novelfeatures disclosed herein.

What is claimed is:
 1. A method for wireless communications, comprising:receiving a first message that indicates a first set of reference signalresources configured for a path loss reference signal; and receiving,based at least in part on the first set of reference signal resourceschanging, a second message that indicates a second set of referencesignal resources configured for the path loss reference signal, whereinthe second message comprises one or more of a medium access control(MAC) control element or downlink control information.
 2. The method ofclaim 1, further comprising: overwriting the first set of referencesignal resources with the second set of reference signal resources basedat least in part on receiving the second message; and estimating a pathloss for an uplink bandwidth part based at least in part on the secondset of reference signal resources associated with the path lossreference signal.
 3. The method of claim 1, wherein the first messagecomprises a radio resource control message for uplink power control. 4.The method of claim 3, wherein the uplink power control comprises one ofmore of physical uplink control channel power control, physical uplinkshared channel power control, or sounding reference signal powercontrol.
 5. The method of claim 4, wherein the sounding reference signalpower control comprises an aperiodic sounding reference signal.
 6. Themethod of claim 4, wherein the sounding reference signal power controlcomprises a semi-persistent sounding reference signal.
 7. The method ofclaim 1, wherein the path loss reference signal comprises one or more ofa channel state information reference signal or a synchronization signalblock.
 8. A method for wireless communications, comprising: transmittinga first message that indicates a first set of reference signal resourcesconfigured for a path loss reference signal; determining that the firstset of reference signal resources has changed to a second set ofreference signal resources; and transmitting, based at least in part onthe first set of reference signal resources changing, a second messagethat indicates the second set of reference signal resources configuredfor the path loss reference signal, wherein the second message comprisesone or more of a medium access control (MAC) control element or downlinkcontrol information.
 9. The method of claim 8, wherein the second set ofreference signal resources overwrites the first set of reference signalresources.
 10. The method of claim 8, wherein the first messagecomprises a radio resource control message for uplink power control. 11.The method of claim 10, wherein the uplink power control comprises oneof more of physical uplink control channel power control, physicaluplink shared channel power control, or sounding reference signal powercontrol.
 12. The method of claim 11, wherein the sounding referencesignal power control comprises an aperiodic sounding reference signal.13. The method of claim 11, wherein the sounding reference signal powercontrol comprises a semi-persistent sounding reference signal.
 14. Anapparatus for wireless communications, comprising: a processor, memoryin electronic communication with the processor; and instructions storedin the memory and executable by the processor to cause the apparatus to:receive a first message that indicates a first set of reference signalresources configured for a path loss reference signal; and receive,based at least in part on the first set of reference signal resourceschanging, a second message that indicates a second set of referencesignal resources configured for the path loss reference signal, whereinthe second message comprises one or more of a medium access control(MAC) control element or downlink control information.
 15. The apparatusof claim 14, wherein the instructions are further executable by theprocessor to cause the apparatus to: overwrite the first set ofreference signal resources with the second set of reference signalresources based at least in part on receiving the second message; andestimate a path loss for an uplink bandwidth part based at least in parton the second set of reference signal resources associated with the pathloss reference signal.
 16. The apparatus of claim 14, wherein the firstmessage comprises a radio resource control message for uplink powercontrol.
 17. The apparatus of claim 16, wherein the uplink power controlcomprises one of more of physical uplink control channel power control,physical uplink shared channel power control, or sounding referencesignal power control.
 18. The apparatus of claim 14, wherein the pathloss reference signal comprises one or more of a channel stateinformation reference signal or a synchronization signal block.
 19. Theapparatus of claim 18, wherein the sounding reference signal powercontrol comprises an aperiodic sounding reference signal.
 20. Theapparatus of claim 18, wherein the sounding reference signal powercontrol comprises a semi-persistent sounding reference signal.
 21. Anapparatus for wireless communications, comprising: a processor, memoryin electronic communication with the processor; and instructions storedin the memory and executable by the processor to cause the apparatus to:transmit a first message that indicates a first set of reference signalresources configured for a path loss reference signal; determine thatthe first set of reference signal resources has changed to a second setof reference signal resources; and transmit, based at least in part onthe first set of reference signal resources changing, a second messagethat indicates the second set of reference signal resources configuredfor the path loss reference signal, wherein the second message comprisesone or more of a medium access control (MAC) control element or downlinkcontrol information.
 22. The apparatus of claim 21, wherein the secondset of reference signal resources overwrites the first set of referencesignal resources.
 23. The apparatus of claim 21, wherein the firstmessage comprises a radio resource control message for uplink powercontrol.
 24. The apparatus of claim 23, wherein the uplink power controlcomprises one of more of physical uplink control channel power control,physical uplink shared channel power control, or sounding referencesignal power control.
 25. The apparatus of claim 24, wherein thesounding reference signal power control comprises an aperiodic soundingreference signal.
 26. The apparatus of claim 24, wherein the soundingreference signal power control comprises a semi-persistent soundingreference signal.